Adding and Subtracting Constants Examples

Solve the equation z + 6 = 3.

We subtract 6 from each side:

Solve the equation x + 5 – 2 = 3(4).

The first step is to simplify the expression on either side of the equation:

x + 3 = 12

Now, we solve as we did earlier:

Solve the equation z – 6 = 5.

If we write z = 5, we've made the quantity on the left heavier by 6 but haven't made the quantity on the right heavier at all. Uh-oh—the scale's a-tippin'. To correctly solve the equation, we need to change each quantity by the same amount. We add 6 to the expression z – 6 and also add 6 to 5 to get:

z – 6 + 6 = 5 + 6
z = 11

Solve the equation 9 – 8 + 2 = x + 4.

First, simplify the expression on each side of the equation:

3 = x + 4

Then subtract 4 from either side:

3 – 4 = x + 4 – 4
-1 = x