Question

Which two integers make a sum of -8 and product of 15

Answer 1

Answer:

x = -3 and y = -5

            or

x = -5 and y = -5

Step-by-step explanation:

Let the integers be x and y

According to question,

x + y = -8

x = -8 - y ------ (i)

x . y = 15

(-8 - y) × y = 15

-8y - y² = 15

y² + 8y + 15 = 0

Using Factorization method,

y² + 5y + 3y + 15 = 0

y(y + 5) + 3(y + 5) = 0

(y + 5)(y + 3) = 0

y + 5 = 0                          y + 3 = 0                                

y = -5                               y = -3

x = -8 - y                           x = -8 - y  

x = -8 - (-5)                       x = -8 - (-3)

x = - 8 + 5                         x = -8 + 3

x = -3                                x = -5