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 -8a - 9a = a - 8x - 4 for a in terms of x.
| 4x - 7 | |
| -\(\frac{1}{9}\)x + \(\frac{4}{9}\) | |
| -\(\frac{1}{18}\)x + \(\frac{1}{9}\) | |
| -x + 6 |