When solving an equation with two variables, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)
Solve -9a + 6a = -4a + 7z + 4 for a in terms of z.
| 7z - 7 | |
| -7z + 6 | |
| -z + 4 | |
| -\(\frac{1}{5}\)z - \(\frac{4}{5}\) |