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8th grade · Math · Unit 7 of 11

Equations with Brackets

Solve ax = b, x ÷ a = b, ax + b = c and a(x + b) = c

What your child practices

Solving one-variable equations, including ones with brackets and negative numbers, checking by substitution, and spotting a common mistake with the distributive property.

Minnesota K-12 Academic Standards benchmark: 8.3.6.3; 8.3.6.1 · multi-step equations that need the distributive property

How we explain it

Children can open this short lesson before they practice.

  1. Undo brackets by dividing both sides, or by expanding.
  2. Do the same thing to both sides.
  3. Check by putting your answer back into the equation.

Example: Solve 2(x + 3) = 14. Divide both sides by 2: x + 3 = 7. Subtract 3: x = 4. Answer: x = 4

Equations with Brackets in Minnesota

In the Minnesota K-12 Academic Standards, this is unit 7 of 11 in 8th grade Math, after Tables, Graphs & Linear Relations and before Exponent Rules.

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: Minnesota Department of Education (MDE)

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

    Sam buys 6 notebooks that cost the same, plus a pen for $2. The total is $32. How much does one notebook cost, in dollars?

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  2. Question 2

    Solve for x: 7x = 28

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  3. Question 3

    Solve for x: x ÷ 7 = 3

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  4. Question 4

    Which equation is equivalent to 5(x + 6) = 25?

    • 5x + 30 = 25
    • x + 30 = 25
    • 5x + 5 = 25
    • 5x + 6 = 25

  5. Question 5

    Solve for x: 3x + 10 = -5

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  6. Question 6

    Which value of x makes 5x + 5 = 15 true?

    • 4
    • 1
    • 3
    • 2

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