Natalie use 112 inches of blue yarn as a border around her rectangular bulletin board. IF the bulletin board is 36 inches wide how long is IT

2 (36) + 2w = 112 [twice the length plus twice the width is 112 inches]

72 + 2w = 112

2w + 72 - 72 = 112 - 72 [Subtract 72 from each side]

2w + 0 = 40 [Evaluate]

2w/2 = 40/2 [Divide both sides by 2]

w = 20

Now let's check.

72 + 2 (20) = 72 + 40 = 112. Looks right from this angle.