Question

Determine two numbers that have a product of 40 but have a sum of 13.

Answer 1

The two numbers are 8 and 5.

Explanation:

Let consider x and y to be these two numbers.

So;

(x) * (y) = 40 ---- (1)

x + y = 13 ----- (2)

From (2), let x = 13 - y

Then;

(13 - y) * y = 40

13y - y² = 40

13y - y² - 40 = 0

-y² + 13y - 40 = 0

Multiply through by (-)

y² - 13y + 40 = 0

By factorization;

(y - 8) (y - 5) = 0

y = 8 or y = 5

CHECK:

8 * 5 = 40

8 + 5 = 13

Therefore, the two numbers are 8 and 5.