SAT Algebra: Linear Equations in One Variable — 16 MCQs with Solutions

Practice 16 original Digital SAT Math questions on linear equations in one variable. Each multiple-choice question includes four answer options, difficulty level, and a detailed worked solution. This independent educational resource is not affiliated with College Board.

SAT-001 | Easy

Solve 5x + 7 = 42.

  1. 5
  2. 6
  3. 7
  4. 8
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Correct answer: C. 7

  1. Subtract 7 from both sides: 5x = 35.
  2. Divide both sides by 5: x = 7.

SAT-002 | Easy

What is x if 3(x − 4) = 21?

  1. 3
  2. 7
  3. 9
  4. 11
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Correct answer: D. 11

  1. Divide by 3: x − 4 = 7.
  2. Add 4 to both sides: x = 11.

SAT-003 | Easy

Solve 2x − 9 = 15.

  1. 3
  2. 6
  3. 12
  4. 24
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Correct answer: C. 12

  1. Add 9 to both sides: 2x = 24.
  2. Divide by 2: x = 12.

SAT-004 | Easy

If x/4 + 3 = 8, what is x?

  1. 5
  2. 11
  3. 20
  4. 32
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Correct answer: C. 20

  1. Subtract 3: x/4 = 5.
  2. Multiply both sides by 4: x = 20.

SAT-005 | Easy

Solve 7 − 2x = −9.

  1. −8
  2. −1
  3. 1
  4. 8
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Correct answer: D. 8

  1. Subtract 7: −2x = −16.
  2. Divide by −2: x = 8.

SAT-006 | Medium

Solve 4(2x − 3) = 3x + 18.

  1. 3
  2. 5
  3. 6
  4. 10
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Correct answer: C. 6

  1. Expand: 8x − 12 = 3x + 18.
  2. Subtract 3x and add 12: 5x = 30.
  3. Divide by 5: x = 6.

SAT-007 | Medium

For what value of x is 5(x + 2) − 3(x − 4) = 30?

  1. 2
  2. 4
  3. 6
  4. 8
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Correct answer: B. 4

  1. Expand: 5x + 10 − 3x + 12 = 30.
  2. Combine like terms: 2x + 22 = 30.
  3. Subtract 22 and divide by 2: x = 4.

SAT-008 | Medium

Solve (x − 3)/5 = (x + 1)/7.

  1. −13
  2. 3
  3. 13
  4. 17
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Correct answer: C. 13

  1. Multiply both sides by 35: 7(x − 3) = 5(x + 1).
  2. Expand: 7x − 21 = 5x + 5.
  3. Subtract 5x, add 21, and divide by 2: x = 13.

SAT-009 | Easy

A streaming service charges a $12 fixed fee plus $4 per movie. If the total bill is $44, how many movies were rented?

  1. 6
  2. 7
  3. 8
  4. 11
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Correct answer: C. 8

  1. Let m be the number of movies: 12 + 4m = 44.
  2. Subtract 12: 4m = 32.
  3. Divide by 4: m = 8.

SAT-010 | Medium

Solve 0.3x + 1.2 = 4.8.

  1. 10
  2. 12
  3. 14
  4. 16
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Correct answer: B. 12

  1. Subtract 1.2: 0.3x = 3.6.
  2. Divide by 0.3: x = 12.

SAT-011 | Medium

The equation 9x − k = 4x + 15 has solution x = 6. What is k?

  1. 9
  2. 12
  3. 15
  4. 21
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Correct answer: C. 15

  1. Substitute x = 6: 54 − k = 24 + 15.
  2. Simplify: 54 − k = 39.
  3. Subtract 39 from 54: k = 15.

SAT-012 | Medium

Solve 2(x + 5) − (x − 7) = 22.

  1. 3
  2. 5
  3. 7
  4. 9
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Correct answer: B. 5

  1. Expand: 2x + 10 − x + 7 = 22.
  2. Combine like terms: x + 17 = 22.
  3. Subtract 17: x = 5.

SAT-013 | Hard

For which value of a does a(x − 2) = 3x + 6 have no solution for x?

  1. −3
  2. 0
  3. 3
  4. 6
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Correct answer: C. 3

  1. Expand: ax − 2a = 3x + 6.
  2. Rearrange: (a − 3)x = 2a + 6.
  3. For no solution, the coefficient of x must be zero while the constant is nonzero.
  4. Setting a = 3 gives 0x = 12, which is impossible.

SAT-014 | Hard

If 2(3x + p) = 6x + 14 is true for every real x, what is p?

  1. 3
  2. 5
  3. 7
  4. 14
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Correct answer: C. 7

  1. Expand: 6x + 2p = 6x + 14.
  2. Subtract 6x: 2p = 14.
  3. Divide by 2: p = 7.

SAT-015 | Medium

A tank initially contains 18 liters. Water flows in at 2.5 liters per minute. After how many minutes will it hold 60 liters?

  1. 14.8
  2. 16.8
  3. 18.2
  4. 31.2
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Correct answer: B. 16.8

  1. Let t denote the number of minutes. Then 18 + 2.5t = 60.
  2. Subtract 18: 2.5t = 42.
  3. Divide by 2.5: t = 16.8 minutes.

SAT-016 | Hard

If (2x − 5)/3 − (x + 1)/2 = 1, what is x?

  1. 11
  2. 17
  3. 19
  4. 23
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Correct answer: C. 19

  1. Multiply each term by 6: 2(2x − 5) − 3(x + 1) = 6.
  2. Expand: 4x − 10 − 3x − 3 = 6.
  3. Combine: x − 13 = 6.
  4. Add 13: x = 19.

Continue SAT Mathematics Preparation

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