PuzzleM8 Learning games for families

Two-step equations

Solve 4x + 5 = 17

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. 4x + 5 = 17The question.

  2. Step 1: Subtract 5 on both sides −5

    On the left, the x part has + 5 with it. Take 5 away from both sides to get rid of it.

    4x = 12

    On the left, the 5 cancels out.

    + 5 is undone by − 5.

  3. Step 2: Divide by 4 on both sides ÷4

    4x means 4 × x. Divide both sides by 4 to get x on its own.

    x = 3

    x is on its own. x = 3.

    Multiplying is undone by dividing.

Answer: x = 3

Check it

Put x = 3 back into the question. If both sides come to the same number, the answer is right.

Left side: 4x + 5 → 12 + 5 = 17

Right side: 17 → 17

✓ Both sides are 17, so x = 3 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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