Question

solve X square + 9 x - 36 =0

Answer 1

=> X²+9x-36=0
=> x²+12x-3x-36=0
=> x(x+12) × -3(x+12)=0
=> (x+12)(x-3)=0
Therefore,
=>(x+12)=0
=> x=-12 &
=>(x-3)=0
=> x=3

Answer 2

x ^2+9x-36
x^2-12x+3x-36
x(x-12) +3(x-12)
(x-12) (x+3)
x=12, x=-3