Question

If x-y = 7 and xy = 9, then the value of x²+ y² is?

Answer 1

(x-y) = 7
Squaring both sides,
(x-y)^2 = 49
x^2 + y^2 - 2xy = 49
x^2 + y^2 = 49 + 2xy = 49+2*9 = 49+18 = 67.

Hope this helps you!

Answer 2

Answer:

Step-by-step explanation:

x-y=(7)^2

(a+b)^2 formula has been written

x^2+y^2-2xy=49

x^2+y^2=49+2×9=67

So that's it

Thank you