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 -2a - 2a = 3a - 6y + 9 for a in terms of y.
| -3y - 7 | |
| -y - 1\(\frac{2}{5}\) | |
| -\(\frac{1}{7}\)y + 1\(\frac{2}{7}\) | |
| \(\frac{4}{5}\)y - 1\(\frac{4}{5}\) |