If , then when a = 8, b could be equal to:

If

, then when a = 8, b could be equal to:
A . C2
B . 4
C . 6
D . 7
E . 8

View Answer

Answer: C

Explanation:

Substitute 8 for a :

. Rewrite 1 as 8/8 and add it to 4 b /8, then cross multiply:

4 b 2 C 8 b C 32 = 64

b 2 C 2 b C 8 = 16

b 2 C 2 b C 24 = 0

( b C 6) × ( b + 4) = 0

b C 6 = 0, b = 6

b + 4 = 0, b + C4