Question

Solve:x^4-34x^2=-225
a. no solution
b.3,-5
c.3,-3,5,-5
d.3,-3

Answer 1

i got x=+/- 5 and +/- 3 so the answer is c :)

Answer 2

x^(4)-34x^(2)=-225

x^(4)-34x^(2)+225=0

(x^(2)-9)(x^(2)-25)=0

(x-3)(x+3)(x^(2)-25)=0

(x-3)(x+3)(x-5)(x+5)=0

x-3=0_x+3=0_x-5=0_x+5=0


x=3,-3,5,-5