x^4 + 2x^3 -8x- 16 = 0?

0 ⤊

solve for x (show work) I think the answers are 2 and -2

2007-09-26 12:31:59 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics

x^4+2x^3-8x-16
= x^3(x+2)-8(x+2)
= (x+2)(x^3-8)
= (x+2)(x^3-2^3)
= (x+2)(x-2)(x^2+2x+4)

this has solutions 2, -2 and 2 complex roots

2007-09-28 02:41:59 · answer #1 · answered by Mein Hoon Na 7 · 0⤊ 0⤋

x^3(x+2) -8(x+2) = 0
(x^3-8)(x+2) = 0
(x+2)^2(x-2)(x+2)=0
x = -2,-2,-2,2

2007-09-26 12:43:25 · answer #2 · answered by ironduke8159 7 · 0⤊ 0⤋