Solve quadratic equations by factoring

x cubed + 3x squared - 4x = 0

x (x^2-3x-4) = 0

factor

x (x-4) (x+1) = 0

x=0

x=4

x=-1

x cubed + 3x squared - 4x = 0

= x^3 + 3x^2 - 4x = 0

=x (x^2 + 3x - 4) = 0

= x (x+4) (x-1) = 0

x = 0

x + 4 = 0 then x = - 4

x - 1 = 0 then x = 1

answer: x = 0, x = - 4 and x = 1