Question

G 1) a2 + 3a – 40 = 0 .
solving quadratic equations

Answer 1

The solution set is {-8, 5}.

Explanation:

a^2 + 3a – 40 = 0 .

We need 2 numbers whose product is -40 and whose sum is +3.

They would be + 8 and - 5, so we have the factors:

(a + 8)(a - 5) = 0

Now either a + 8 = 0 or a - 5 = 0, so:

a = -8 or 5.