Solve Equations Using the Subtraction and Addition Properties of Equality: example 2.7

Solve: $5 (n - 4) - 4 n = −8 .$

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: $5 (p - 3) - 4 p = −10 .$

How did it go?


Distribute on the left.
Use the Commutative Property to rearrange terms.
Combine like terms.
Each side is as simplified as possible. Next, isolate $n$ .
Undo subtraction by using the Addition Property of Equality.
Add.
Check. Substitute $n = 12$ .
	The solution to $5 (n - 4) - 4 n = −8$ is $n = 12 .$


Distribute on the left.
Use the Commutative Property to rearrange terms.
Combine like terms.
Each side is as simplified as possible. Next, isolate $n$ .
Undo subtraction by using the Addition Property of Equality.
Add.
Check. Substitute $n = 12$ .
	The solution to $5 (n - 4) - 4 n = −8$ is $n = 12 .$