Digital SAT practice

Reach your peak.

A quick run every day, an explanation for every question, and full-length tests on official timing.

Take the free diagnostic
Start here: 20 questions, about 28 minutes. You see your level in every domain and which lessons to take first. Free, no card. You also get 36 practice questions a day: 9 easy, 9 medium, 9 hard and 9 challenging. See what’s free
The DailySTEP 1
  • Three hearts. A miss costs one.
  • Streaks pay. ×2 from three in a row, ×3 from six.
  • Your longest streak. Beat it tomorrow.

Full-length tests

The real test, rehearsed.

98 questions across four modules, in the digital SAT’s order and on its timing, with a highlighter, a question map and a timer you can see.

A Peakscor full-length test in progress: Reading and Writing, Test A, Module 1 of 4, question 7 of 27, with the passage, four answer choices, a highlighter, a 24:18 timer and Flag, Back and Next buttons.

How it works

One run a day. One skill at a time.

  1. 1

    Play the Daily.

    A quick run with three hearts. String right answers together and the questions get harder and the points multiply.

  2. 2

    Miss one, learn why.

    Every question is tagged by domain and skill, and every answer comes with an explanation.

  3. 3

    Drill that skill.

    Practice any single skill at any difficulty, or just the questions you got wrong.

  4. 4

    Beat your best.

    Come back tomorrow and climb. Progress shows your accuracy and your strongest skills.

Built around the real SAT blueprint.

Every question is tagged by section, domain, skill and difficulty, so you can practice exactly what you need. Full tests run like test day: two Reading & Writing modules, a break, then two Math modules.

Explanations

Every answer, explained.

Not just the right letter: how to get there, and why the tempting answer is wrong.

MathProblem-Solving and Data AnalysisHard

A store raises the price of a jacket by 20%. Later, it lowers the new price by 20%. The final price is what percent of the original price?

A80%
B96%Correct
C100%The trap
D104%

Check with $100: $100then$120then$96

  1. Turn each change into a multiplier.

    Up 20% means × 1.20. Down 20% means × 0.80.

  2. Apply them in order.

    1.20 × 0.80 = 0.96

  3. Read the answer.

    The final price is 96% of the original. That’s B.

  4. Why not 100%?

    The 20% cut is taken from the higher price, so it removes more than the 20% increase added.

Test day

What test day looks like.

Every Peakscor full test follows this order. In the standard tests, the second module of each section adapts to how you did on the first.

  1. Reading & Writing · Module 1

    27 questions32 min

  2. Reading & Writing · Module 2

    27 questions32 min

    Adapts to how you did on Module 1.
  3. Break

    10 min

  4. Math · Module 1

    22 questions35 min

  5. Math · Module 2

    22 questions35 min

    Adapts to how you did on Module 1.

98 questions · 2 hr 14 min of testing, plus the break

Peakscor by the numbers

  • 36free practice questions every day
  • 98questions in every full-length test
  • 1,023SAT vocabulary words
  • 1.5×extended-time option on every test

Plans

Free every day. Pro when you’re serious.

The free plan is the real thing, not a trial. Pro removes the limits. Peak adds the full course and a plan to test day.

Free

$0no card needed

  • The Daily, every day
  • 36 practice questions a day, each with an explanation: 9 easy, 9 medium, 9 hard, 9 challenging
  • Full-length Test A and Challenge Test 1
  • All 1,023 vocabulary words: browse, flashcards and quiz
  • Each Learn module’s overview and first lesson, and the 20-question diagnostic
  • PEAK Survivor’s first map, plus the opening levels of Hole and Peak Defense
Start free daily practice

Pro

$20a month, or $200 a year

  • Everything in Free
  • Unlimited practice, no daily limit
  • Every full-length test and Challenge test
  • Every game map and level, with progress saved
See Pro

Peak

$29a month, or $280 a year

  • Everything in Pro
  • The full Learn course: every lesson and mastery quiz
  • Peak Plan, day by day to test day
See Peak

Prices in US dollars. Cancel anytime.

FAQ

Questions, answered.

The Daily, plus 36 practice questions every day: 9 easy, 9 medium, 9 hard and 9 challenging, each with a full explanation. Full-length Test A, Challenge Test 1 and all 1,023 vocabulary words are free too, as are the 20-question diagnostic, each Learn module’s overview and first lesson, and PEAK Survivor’s first map. No card needed.

Pro is $20 a month or $200 a year: unlimited practice with no daily limit, plus every full-length test and Challenge test, and every game map and level. Peak is $29 a month or $280 a year: everything in Pro, plus the full Learn course and Peak Plan. Cancel anytime from your account.

98 questions across four modules, in the digital SAT’s order: Reading & Writing Module 1 and Module 2 (27 questions each), a 10-minute break, then Math Module 1 and Module 2 (22 questions each). On official timing that’s 2 hr 14 min of testing. You get estimated section scores and a total at the end.

Yes. In the standard full-length tests, Module 2 of each section is the harder version if you get 60% or more of Module 1 right, and the easier version if you don’t. Challenge tests use the hardest material throughout.

Official timing, extended 1.5× time, or untimed, on every test, including the free ones. Extended time allows 48 minutes for each Reading & Writing module and about 52 for each Math module. Untimed removes the clock so you can focus on accuracy.

A quick run with three hearts. Each right answer builds your streak: the questions get harder as it grows, and your points multiply (×2 from three in a row, ×3 from six). A miss costs a heart and drops you back to easy. Best is your longest streak.

Every day at midnight Central Time. You get a fresh 9 easy, 9 medium, 9 hard and 9 challenging.

No. Peakscor is an independent SAT practice tool, not affiliated with the College Board. Scores shown are estimates.

Your next point starts today.

Free, no card.

Nonlinear equations and systems · Lesson 5

Systems with a nonlinear equation

A nonlinear system has at least one equation that isn't a line, most often a parabola and a line. A solution is an ordered pair (x,y)(x, y) that makes both equations true, which is a point where the two graphs meet.

Substitute. When both equations start with y=y =, set the right sides equal. For y=x2−3y = x^2 - 3 and y=2xy = 2x: x2−3=2xx^2 - 3 = 2x, so x2−2x−3=0x^2 - 2x - 3 = 0, (x−3)(x+1)=0(x - 3)(x + 1) = 0, and x=3x = 3 or x=−1x = -1.

**Find yy too.** Put each xx into the simpler equation: y=2(3)=6y = 2(3) = 6 and y=2(−1)=−2y = 2(-1) = -2. The solutions are (3,6)(3, 6) and (−1,−2)(-1, -2).

Count with the discriminant. After substituting, the quadratic in xx has as many real solutions as the graphs have intersection points. Discriminant positive: the line crosses the parabola twice. Zero: the line just touches it once. Negative: they never meet. For *exactly one solution, what is kk?*, set this discriminant to 0.

Reading a graph. When the graphs are given, each intersection point is a solution. A point that is on only one of the graphs, such as the parabola's vertex or the line's yy-intercept, is not a solution of the system.

The graphs of y = x^2 - 3 and y = 2x−4−3−2−112345−4−22468100xy(-1, -2)(3, 6)(0, -3)
The graphs of y=x2−3y = x^2 - 3 and y=2xy = 2x An upward-opening parabola with its vertex at (0, -3) and a line through the origin with slope 2. The line crosses the parabola at exactly two points, (-1, -2) and (3, 6). These are the two solutions of the system.

Worked example Easy

y=x2y = x^2

y=x+6y = x + 6

Which ordered pair (x,y)(x, y) is a solution to the given system of equations?

  1. (−3,9)(-3, 9)
  2. (0,6)(0, 6)
  3. (2,4)(2, 4)
  4. (3,9)(3, 9)Answer

How to solve it

  1. Both equations give yy, so set them equal: x2=x+6x^2 = x + 6.
  2. Standard form: x2−x−6=0x^2 - x - 6 = 0, so (x−3)(x+2)=0(x - 3)(x + 2) = 0 and x=3x = 3 or x=−2x = -2.
  3. Find yy: when x=3x = 3, y=9y = 9; when x=−2x = -2, y=4y = 4. The solutions are (3,9)(3, 9) and (−2,4)(-2, 4).
  4. Only (3,9)(3, 9) is among the choices. Check it in both equations: 9=329 = 3^2 and 9=3+69 = 3 + 6.

Why each choice is right or wrong

  • A. Incorrect. This reads the solution straight off the factor x−3x - 3 with its sign kept, which gives x=−3x = -3. The point is on the parabola, since (−3)2=9(-3)^2 = 9, but not on the line: −3+6=3-3 + 6 = 3, not 9.
  • B. Incorrect. (0,6)(0, 6) is the line's yy-intercept. It is on the line but not on the parabola, since 02=00^2 = 0.
  • C. Incorrect. This reads the solution straight off the factor x+2x + 2 with its sign kept, which gives x=2x = 2. The point is on the parabola, since 22=42^2 = 4, but not on the line: 2+6=82 + 6 = 8, not 4.
  • D. Correct. x2=x+6x^2 = x + 6 gives x=3x = 3 or x=−2x = -2, and (3,9)(3, 9) satisfies both equations: 32=93^2 = 9 and 3+6=93 + 6 = 9.

Worked example Medium

y=2x2−5x+1y = 2x^2 - 5x + 1

y=x−3y = x - 3

How many solutions does the given system of equations have?

  1. Zero
  2. Exactly one
  3. Exactly twoAnswer
  4. Infinitely many

How to solve it

  1. Set the right sides equal: 2x2−5x+1=x−32x^2 - 5x + 1 = x - 3.
  2. Subtract xx and add 3: 2x2−6x+4=02x^2 - 6x + 4 = 0. Divide by 2: x2−3x+2=0x^2 - 3x + 2 = 0.
  3. Discriminant: 9−8=19 - 8 = 1, which is positive, so there are two solutions. (Factoring confirms it: (x−1)(x−2)=0(x - 1)(x - 2) = 0, giving the points (1,−2)(1, -2) and (2,−1)(2, -1).)

Why each choice is right or wrong

  • A. Incorrect. This adds xx instead of subtracting it, which gives 2x2−4x+4=02x^2 - 4x + 4 = 0 with discriminant 16−32=−1616 - 32 = -16. Subtracting xx gives 2x2−6x+4=02x^2 - 6x + 4 = 0.
  • B. Incorrect. This reads the discriminant's value, 1, as the number of solutions. A positive discriminant means two solutions, whatever its size.
  • C. Correct. Substituting gives x2−3x+2=0x^2 - 3x + 2 = 0, whose discriminant is 1, so there are two solutions: (1,−2)(1, -2) and (2,−1)(2, -1).
  • D. Incorrect. A line and a parabola can meet at most twice. Infinitely many solutions would need the two equations to describe the same graph.

Worked example Hard

y=x2−6x+ky = x^2 - 6x + k

y=2x−3y = 2x - 3

In the given system, kk is a constant. The system has exactly one solution. What is the value of kk?

  1. 66
  2. 1313Answer
  3. 1616
  4. 1919

How to solve it

  1. Set the right sides equal: x2−6x+k=2x−3x^2 - 6x + k = 2x - 3.
  2. Move everything to the left: subtract 2x2x and add 3, so x2−8x+(k+3)=0x^2 - 8x + (k + 3) = 0.
  3. Exactly one solution means the discriminant is 0: 64−4(k+3)=064 - 4(k + 3) = 0, so k+3=16k + 3 = 16 and k=13k = 13.
  4. Check: with k=13k = 13, the equation is x2−8x+16=(x−4)2=0x^2 - 8x + 16 = (x - 4)^2 = 0, so the line touches the parabola only at x=4x = 4.

Why each choice is right or wrong

  • A. Incorrect. This computes the discriminant before moving 2x2x, using b=−6b = -6: 36−4(k+3)=036 - 4(k + 3) = 0 gives k=6k = 6. After moving 2x2x, the xx-coefficient is −8-8.
  • B. Correct. Substituting gives x2−8x+(k+3)=0x^2 - 8x + (k + 3) = 0. A discriminant of 0 needs k+3=16k + 3 = 16, so k=13k = 13.
  • C. Incorrect. 16 is the value of k+3k + 3, the whole constant term. Subtract 3 to get kk.
  • D. Incorrect. This subtracts 3 instead of adding it when moving −3-3 to the left, which gives k−3=16k - 3 = 16 and k=19k = 19. Moving −3-3 across means adding 3.

Trap A point on only one graph

Choices often include points that satisfy one equation but not the other: the vertex, an intercept, or a solution with the wrong sign. Before you pick an ordered pair, substitute it into both equations.

Trap Stopping at x

Substitution gives the xx-coordinates first. If the question asks for yy, an ordered pair or a sum such as x+yx + y, finish by putting each xx into one of the equations.

Desmos When Desmos is faster

Type both equations exactly as given, such as y=x2−3y = x^2 - 3 and y=2xy = 2x. Click each point where the graphs cross to see its coordinates. Count the crossings to answer how many solutions.

For a constant such as kk, add the slider Desmos offers and type each answer choice as the slider's value. Watch for the value where the line just touches the parabola.

A line that nearly touches a parabola can look tangent when it isn't. If the picture is close, check with the discriminant of the combined equation.

Your progress

How you’re doing across daily practice and full-length tests.

Practice

Choose a section, then practice a whole domain or drill a single skill.

Difficulty
Status
Session
Timing

Full-length tests

Each test mirrors the digital SAT: 98 questions across four modules, 2 hr 14 min on official timing.

A little harder than the real SAT. These tests can run slightly tougher than test day, which makes them good practice: if you can handle these, the real one should feel easier. No question appears in more than one test, Challenge Tests included.

Challenge Tests Hardest of the hardest

Same 98-question format, but every question is drawn from the toughest SAT material: Challenging-tier math throughout and the hardest reading.

Vocab

Study the classic SAT vocabulary list. Browse, flip flashcards, or quiz yourself.

Free every day. Pro when you're serious.

Practice free every day. Pro removes the limits. Peak adds the full course and a plan to test day.

FREE

$0forever
 
  • ✓ 9 easy + 9 medium + 9 hard + 9 challenging daily
  • ✓ Practice by any SAT domain
  • ✓ Explanations on every question
  • ✓ Test A and Challenge Test 1
  • ✓ Each Learn module’s overview and first lesson
  • ✓ The 20-question Learn diagnostic
  • ✓ PEAK Survivor’s first map, plus the opening levels of Hole and Peak Defense

PRO

$200/ year
About $16.67 a month, save $40
  • ✓ Everything in Free
  • ✓ Unlimited daily practice
  • ✓ Every full-length and Challenge test
  • ✓ Every game map and level, with progress saved
Full course and plan

PEAK

$280/ year
About $23.33 a month, save $68
  • ✓ Everything in Pro
  • ✓ Every Learn lesson, summary and mastery quiz
  • ✓ Peak Plan: a day-by-day plan to test day
  • ✓ Cancel anytime

Prices in USD. Switch or cancel your plan at any time.

▦ Calculator
Drag the bar to move it, and the corner to resize it