# How do you solve 15 - z = 6?

Jun 10, 2018

$z = 9$
$15 - 9 = 6$

#### Explanation:

$15 - z = 6$

The goal of this equation is solve for the value of the variable, $z$. This is a one-step problem. To do this, we want to make $z$ by itself to find its value. Because $15$ is also on the same side, and we only want $z$, we'll subtract $15$ to cancel out positive $15$.

Because we subtract $15$ to one side, we'll have to subtract $15$ from the other side. So, you're left with this:

$- z = - 9$

Because you can't have a negative variable, divide by $- 1$ to make the equation positive. Recall that two negatives create a positive, so:

$z = 9$

Confirm that this is right by plugging it into your equation:

$15 - z = 6$
$15 - 9 = 6$
$6 = 6$

This is correct.