PuzzleM8 Learning games for families

Two-step equations

Solve 9x + 20 = 119

The aim is to get x on its own. Whatever we do to one side, we do to the other, so the equation stays balanced. This one takes 2 steps.

  1. 9x + 20 = 119The question.

  2. Step 1: Subtract 20 on both sides −20

    On the left, the x part has + 20 with it. Take 20 away from both sides to get rid of it.

    9x = 99

    On the left, the 20 cancels out.

    + 20 is undone by − 20.

  3. Step 2: Divide by 9 on both sides ÷9

    9x means 9 × x. Divide both sides by 9 to get x on its own.

    x = 11

    x is on its own. x = 11.

    Multiplying is undone by dividing.

Answer: x = 11

Check it

Put x = 11 back into the question. If both sides come to the same number, the answer is right.

Left side: 9x + 20 → 99 + 20 = 119

Right side: 119 → 119

✓ Both sides are 119, so x = 11 is right.

Now try it yourself

Solve this one in Algebra Balance. You choose each step, and it explains what happened, with hints if you get stuck.

Practise this in Algebra Balance

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