Answer:
c. a: 4
b: 12
c: 9
4x² +12x+9=0
(2x+3)(2x+3)= 0
(2x+3)²=0 {square root both sides}
2x+3=0
2x=-3
x= -3/2
Answer:
He is 20 at oldest, or 
Step-by-step explanation:
The first step in finding a possible age is:
Subtract 10 from 51, and you get 41. Divide by 2, and you get about 20.5.
This means Joe is younger than or 20 years old.
Their slopes would be the same but their positions or points ( if the lines were on a graph) would be different.
3.1
3.6
4.2
4.5
4.9
5.0
Hope it helps