How do you solve x( x + 3) - 40= 0x(x+3)40=0?

1 Answer
Apr 16, 2018

x=5, x=-8

Explanation:

First expand brackets:

x(x+3)-40=0x(x+3)40=0 becomes x^2+3x-40=0x2+3x40=0

Then solve as normal quadratic:

x^2+3x-40=0x2+3x40=0
(x-5)(x+8)=0(x5)(x+8)=0

If x-5=0x5=0 then x=5x=5
If x+8=0x+8=0 then x=-8x=8

Hope this helps!