If x- y = 7 and xy = 9, find the value fo x2+y2
Given that, x – y = 7
Squaring both sides, we get
(x – y)2 = (7)2
x2 + y2 – 2xy = 49
Its given that xy = 9,
x2 + y2 – 2 (9) = 49
x2 + y2 = 49 + 18
x2 + y2 = 67