Question

Let a=x^2+4. Use a to find the solutions for the following equation:

(x^2+4)^2+32=12x^2+48
Which of the following are solutions for x?
A.-8
B.-2
C.4
D. 0
E.2
F.-4
G.8

Answer 1

-2,0, 2(+)

Explanation:

Answer 2

(x^2+4)^2 + 32 = 12x^2 + 48 .... a = x^2 + 4
(x^2 + 4)^2 + 32 = 12(x^2 + 4)
a^2 + 32 = 12a
a^2 - 12a + 32 = 0
(a - 8)(a - 4) = 0
a = 8 and a = 4

for a = 8 ... 8 = x^2 + 4 ... x^2 = 4 ... x = +/- 2
for a = 4 ... 4 = x^2 + 4 ... x^2 = 0 ... x = 0

x = -2, 0, +2 so your answer is going to be e