Question

if x+y=5 and xy =6 then find x³+y³

Answer 1

Hi friend!!

Given, x+y=5--------(1)

Squaring on both sides, we get

x²+y²+2xy=25

Given, xy=6-----(2)

→x²+y²+2(6)=25

x²+y²+12=25

x²+y²=13--------(3)

Now, x³+y³=(x+y)(x²+y²-xy)

From (1),(2),(3) we get

x³+y³=5(13-6)

=5(7)=35


I hope this will help you ;)

Answer 2

Hii friend!!

x^3 + y^3 = (x +y) ( x^2 + y^2 -xy )
= (5) ( 5^2 - 6 )
= 5 ( 25 -6 )
= 5× 19
= 95

Hope it will help you