Question

Find the values of x+y if x^{2} + y^{2} =36 and xy=-10.

Answer 1

Hint:

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

Answer 2

so how do you go about solving the problem?

Answer 3

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

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

How about that?

Answer 4

ohh okay so it ends up being 16=(x+y)^2 and then simplifying it becomes 4=x+y thanks

Answer 5

very good