Answer:
x = 4 and -10
Step-by-step explanation:
Given the equation
x²+6x-40= 0
The common factors to use for the factorisation are +10 and -4
x²+(10x-4x)-40=0
(x²+10x)-(4x-40) = 0
x(x+10)-4(x+10) = 0
(x-4)(x+10) = 0
x-4 =0 and x+10 = 0
x = 4 and x = -10
