4x^2+16x=-13

Question

how do you work this out?

Answer 1

4x²+16x=-13,

x²+4x=-13/4,

x²+4x+4=4-13/4=¾,

(x+2)²=¾,

x+2=±√3/2,

x=-2-√3/2, x=-2+√3/2, that is: x=-2.8660, -1.134 approx.