The additive inverse of a number undoes the effect of adding that number. This means that, for example, the effect of adding a number by subtracting the same number can be undone. So, if 7 is added to 4, the result is 11. If 7 is subtracted from 11, the addition is undone, and the result is 4.

4 + 7 = 11 and 11 – 7 = 4

Multiplication and division are related in the same way: They are inverse operations that undo each other. If 6 is multiplied by 3, the result is 18. Then 18 can be divided by 3 to undo the multiplication, and the result is 6.

6 × 3 = 18 and 18 ÷ 3 = 6

Most mathematical operations have an inverse operation that undoes or reverses its effect. The squaring of a number, for example, as in 7² = 49, can be undone by taking the square root. The square root of 49 is 7. Thus, squaring and taking the square root are also inverse operations.

Inverse operations can also be used to find the additive inverse...