Question

find the roots of the quadratic equation y=x^2+7x-18 by factoring

Answer 1

x^2+7x-18=0
x^2+9x-2x-18=0 ( splitting middle term)
x(X+9)-2(x+9)=0
(x-2) * (X+9) =0
Therefore, X=+2 or -9