If the sum and the product of two numbers are 8 and 15 respectively, find the sum of their cubes.
54 Likes
Let two numbers be x and y.
Given,
x + y = 8 and xy = 15.
We know that,
⇒ x3 + y3 = (x + y)3 - 3xy(x + y)
⇒ x3 + y3 = 83 - 3(15)(8)
⇒ x3 + y3 = 512 - 360
⇒ x3 + y3 = 152.
Hence, x3 + y3 = 152.
Answered By
32 Likes
If a - b = 7 and a2 + b2 = 85, then find the value of a3 - b3.
If the number x is 3 less than the number y and the sum of the squares of x and y is 29, find the product of x and y.
If x2 + y2 = 9 and xy = 8, then x + y is equal to
25
5
-5
±5