Question

How do you solve `x^2 + 3x - 40 = 0`?

Answer 1

The answers for `x^2+3x−40=0` are -8 and 5.

Explanation:

For this problem, we are able to factor. Since 8 and 5 are both factors of 40, and since 8-5=3, we will use 8 and 5 in our binomial equation: `(x+8)(x-5)=40`. Just to prove that this is correct, let's multiply the two together: `x^2-5x+8x-40=x^2+3x-40`. From here, we can use the zero product property to get our answers: `x+8=0, x-5=0`. Subtract 8 from the first equation and subtract 5 from the second equation to get our answers, -8 and 5.