Question

If X + 5 is equal to 5 and xy = 6 then find the value of x cube + y cube

Answer 1

Step-by-step explanation:

As, (x−y)^2 = (x+y)^2 − 4xy

(Identity) (x-y)^2 = 25 - 24 or

, x−y=+1,−1now equation 1 => x+y=5x+y=5and equation 2 => x−y=+1,−1By solving the two equation we get,x=3,y=2or,x=2,y=3

So, Case 1: x=3,y=2:

x^3-y^3 = 19

Case 2: x=2,y=3:

x^3-y^3 = -19