Use a General Strategy to Solve Linear Equations: example 2.38

Solve: $− (y + 9) = 8 .$

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Solve: $− (y + 8) = −2 .$

How did it go?


Simplify each side of the equation as much as possible by distributing.
The only $y$ term is on the left side, so all variable terms are on the left side of the equation.
Add $9$ to both sides to get all constant terms on the right side of the equation.
Simplify.
Rewrite $- y$ as $−1 y$ .
Make the coefficient of the variable term to equal to $1$ by dividing both sides by $−1$ .
Simplify.
Check:
Let $y = −17$ .


Simplify each side of the equation as much as possible by distributing.
The only $y$ term is on the left side, so all variable terms are on the left side of the equation.
Add $9$ to both sides to get all constant terms on the right side of the equation.
Simplify.
Rewrite $- y$ as $−1 y$ .
Make the coefficient of the variable term to equal to $1$ by dividing both sides by $−1$ .
Simplify.
Check:
Let $y = −17$ .