Question

if x+y = 7 and xy= 9 , find the value of x2+y2

Answer 1

ur answer is 31
hope this helps you...

Answer 2

x+y=7, xy=9
x+y=7
squaring on both sides
(x+y)^2 = 49
x^2 + y^2 + 2xy=49
x^2 + y^2 + 2(9)=49
x^2+y^2+ 18=49
x^2+y^2= 49-18
x^2+y^2=31 is answer