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7th grade · Math · Unit 4 of 20

Two-Step Equations

Undo, undo, solve for x

What your child practices

Solving equations like 3x + 5 = 26 by undoing each step on both sides, writing equations from word problems and checking solutions.

New York State Learning Standards learning standard: NY-7.EE.4 · writing and solving two-step equations from problems in context

How we explain it

Children can open this short lesson before they practice.

  1. Keep the equation balanced: do the same to both sides.
  2. Undo the adding or subtracting first.
  3. Then undo the multiplying or dividing.

Example: 2x + 3 = 11 Subtract 3 from both sides: 2x = 8. Divide both sides by 2: x = 4. Answer: x = 4

Two-Step Equations in New York

In the New York State Learning Standards, this is unit 4 of 20 in 7th grade Math, after Fractions, Decimals & Percents and before Circles.

Gradelings describes a child's practice on this unit as Beginning, Approaching, Meeting or Exceeding (Four practice steps). That reflects practice, not a report-card mark: the teacher decides the mark.

Source: New York State Education Department (NYSED)

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Solving 3x + 8 = 44, you reach 3x = 36. Which step gets x by itself?

    • Subtract 3 from both sides
    • Divide both sides by 3
    • Divide only the left side by 3
    • Multiply both sides by 3

  2. Question 2

    On a balance scale, 9 identical bags of marbles plus 20 loose marbles balance 74 loose marbles. How many marbles are in each bag?

    ⚖️9x + 20 = 74

    answer box

  3. Question 3

    Solve: 6n − 16 = 8

    • 3
    • 4
    • 5
    • 24

  4. Question 4

    Which equation matches this sentence? "Three times a number, plus 2, equals 32."

    • 3n + 2 = 32
    • 2n + 3 = 32
    • 3n − 2 = 32
    • 3(n + 2) = 32

  5. Question 5

    A climbing gym charges a $33 membership fee plus $4 per visit. Sam paid $57 in total. How many visits was that?

    answer box

  6. Question 6

    Is x = 9 a solution of 7x − 15 = 48?

    7x − 15 = 48

    • No
    • Yes

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