Answer:
60=2(20)+2x
x=10
Step-by-step explanation:
First, let's write some equations. I wrote 60=2(20)+2x, where x is the length of the room. To solve, first multiply 2 times 20 for 40 (60=40+2x). Then, I subtracted 40 from both sides (20=2x). Finally, I divided on both sides by 2 (10=x).
That is the Distributive property of equality