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 -4a - a = 9a - 8y + 9 for a in terms of y.
| 4y + 2 | |
| 5\(\frac{1}{2}\)y - \(\frac{1}{2}\) | |
| \(\frac{4}{5}\)y + 1\(\frac{1}{5}\) | |
| \(\frac{7}{13}\)y - \(\frac{9}{13}\) |