Question 173410
x(x-3) = 40

Expand the equation

x^2-3X=40

subtract 40 from both sides

x^2-3X-40=0

Find possible factors for 40

(40,1) (2,20) (8,5)

We see that the 40 has a negative sign which means that one of the factors is negative.

Then we find which two factors when added together can give you -3

I can see from the list that the only possible answer is 5,8


(x-8)(x+5)=0 is the factored form of the above equation


Therefore the answers are x=8 and x=-5