Question

Solve the equation 9b2 + 30b + 25 =0

Answer 1

C. b = -5/3

Explanation:

9b² + 30b + 25 = 0

We can factor: two numbers that add up to 30 and its' product is 225: 15 & 15.

So we have 9b² + 15b + 15b + 25 = 0.

We can change this to (3b + 5) (3b + 5), or (3b + 5)².

This means there is only one solution: 3b + 5 = 0.

This can be turned into 3b = -5 -> b = -5/3.

Answer 2

C. b = -5/3

Explanation:

9b2 + 30b + 25 =0

(3b)^2 + 30b +(5)^2 = 0 <---perfect square

(3b + 5)^2 = 0

(3b + 5) = 0

3b = -5

b = -5/3

Answer

C. b = -5/3