Question

If x+y=8 and xy=15, find x2+ y2 .

Answer 1

GIVEN :

x + y = 8

xy = 15.

Required To Find : x^2 + y^2.

SOLUTION :

we know that,

( x+y )^2 = x^2 + y^2 + 2xy

x^2 + y^2 = ( x + y )^2 - 2xy

= 8^2 - 2×15

= 64 - 30

x^2 + y^2 = 34.

RESULT :

x^2 + y^2 = 34