Question

Solve this polynomial using factor by grouping x³+2x²+4x+8=0 show work

Answer 1

x³+2x²+4x+8=0

Rearrange

x³ + 4x + 2x²+ 8 = 0

x ( x² + 4 ) + 2( x² + 4) = 0

(x + 2) ( x² + 4) = 0

The factors are;

(x + 2) (x² + 4)

(x²+ 4) can further be simplified to give (x- 2i) (x + 2i)