Question

Solve the following quadratic equation by factorization.

$x^2+x-20=0$

Answer 1

We have,

$x^2+x-20=0$

$\Rightarrow x^2+(5-4)x-20=0$

$\Rightarrow x^2+5x-4x-20=0$

$\Rightarrow x(x+5)-4(x+5)=0$

$\Rightarrow (x+5)(x-4)=0$

If $x+5=0,x=-5$

If $x-4=0,x=4$

Hence, this is the answer.