Solving linear equations · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Solving for x

Mathematics · Algebra · ages 11-14
Name ______________________   Date ____________

  1. Solve the equation 6x = 21.

    Answer: ______________

  2. Solve the equation x + 7 = 15.

    Answer: ______________

  3. Solve: x + 6 = 10. What is x?

    • 16
    • 6
    • 4

  4. To solve 2x - 5 = 9, the first step is to add 5 to both sides.

    Circle one:   True   False

  5. Solve: 4x + 5 = x + 20. What is x?

    • 3
    • 15
    • 5

  6. Solve the equation 4(x - 1) = 12.

    Answer: ______________

  7. Solve the equation 5x = 2x + 12.

    Answer: ______________

  8. Solve the equation x/4 + 3 = 7.

    Answer: ______________

  9. I am thinking of a number. If I double it and add 1, I get the same answer as when I triple it and take away 10. What is the number?

    • 8
    • 11
    • 13
    • 9

  10. Solve: -2x + 3 = 9. What is x?

    • 3
    • -3
    • -6
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Answer key

For grown-ups. Fold this page away before handing over the rest.

Solving for x W1-mt_QhFEDyIwSO-s1

  1. 3.5 · x is multiplied by 6, so divide both sides by 6 to isolate x.
  2. 8 · Undo the adding of 7 by subtracting 7 from both sides, and x is left on its own.
  3. 4 · Subtract 6 from both sides: x = 10 - 6 = 4.
  4. True · Adding 5 undoes the subtraction, giving 2x = 14. Then divide by 2.
  5. 5 · Subtract x from both sides to get 3x + 5 = 20, then subtract 5 and divide: x = 5.
  6. 4 · Expand the brackets, then isolate x.
  7. 4 · Subtract 2x from both sides to gather the x terms on one side, then divide by 3.
  8. 16 · Subtract 3 from both sides first, then multiply both sides by 4 to undo the division.
  9. 11 · The two instructions give the equations 2x + 1 and 3x - 10. Setting them equal and solving gives x = 11.
  10. -3 · Subtract 3: -2x = 6. Divide by -2: x = -3, since a positive divided by a negative gives a negative answer.
Worksheet · LightMySky