Exercise 20 Page 443

r=7

Practice makes perfect

To solve the equation, we have to isolate r on one side. Using the Subtraction Property of Equality, we can subtract 2 from both sides of the equation. This will eliminate addition on the right-hand side and isolate r.

9=r+2

LHS- 2=RHS- 2

9- 2=r+2- 2

Subtract terms

7=r

Rearrange equation

r=7

To check that this solution is correct, let's substitute r=7 into the original equation and simplify.

9=r+2

r= 7

9? = 7+2

Add terms

9=9 ✓

Because the left-hand side and right-hand side are equal, r=7 is the correct solution.

Guided Practice p.440

Independent Practice p.441-442

H.O.T. Problems p.442

Standardized Test Practice p.442-444

Extra Practice p.443

Common Core Review p.444

Hints