Question

Which of the following when added to 4a^2+9 will result in a perfect square for all integer values of a?


(A) 0
(B) 3a
(C) 6a
(D) 9a
(E) 12a

Answer 1

Answer:

(D) 9a

Step-by-step explanation:

Given

4a^2 + 9

Add 9a to the expression

4a^2 + 9 + 9a

This can be written as

(2a)^2 + (3)^2 + (3)^2 a

Answer 2

Answer:

E. 12a

Step-by-step explanation:

TBH no idea why thats correct.