Question

iif the sum and product of two numbers are 8 and 15 respectively, find the sum of their cubes​

Answer 1

Answer:  Let the two numbers be x and y

Sum of numbers = 8

x+y = 8

x = 8-y

Product of numbers = 15

xy = 15

y(8-y) = 15

8y - y² = 15

y² - 8y + 15 =0

y² - 5y -3y +15 =0

y(y-5) -3(y-5) = 0

(y-5)(y-3) = 0

y = 5 or y = 3

If y = 5 then x = 3

If y = 3 then x = 5

the two numbers are 3 and 5

Their cubes are 27 and 125