Exercises 512 Find the integer pair product and sum Solution

Exercises 5-12: Find the integer pair product and sum.

Solution

5)

product is = 28 = (x*y)

sum = 11 = (x+y)

x= 28/y

28/y +y = 11

11-y = 28/y

11y-y² = 28

y² -11y +28 = 0

solivng we get

y = 7, 4

and x as

x = 4,7

9)

xy = -50

x+y = 5

x= -50/y

-50/y +y = 5

5-y = -50/y

5y -y² = -50

y² -5y -50 = 0

y = 10 , -5

and x as

x = -5 , 10

11)

xy = 28

x+y = -11

x = 28/y

28/y +y = -11

-11-y = 28/y

-11y-y² = 28

y² -28 +11y = 0

y = -7, -4

and x = -4, -7