Answer:
a = 3
Step-by-step explanation:
1) Simplify 5a - 9 + a to 6a - 9.

2) Add 9 to both sides.

3) Simplify 9 + 9 to 18.

4) Divide both sides by 6.

5) Simplify 18/6 to 3.

Therefor, the answer is, a = 3.
Answer:
b & c for sure
Step-by-step explanation:
............
Answer:
21
Step-by-step explanation:
A proportional dimension will change the perimeter by the factor of itself. And will change the area by the factor of the dilation squared.