If x+y=-4, and x=6/y, what is the value of x^2+y^2? Choices.
A) 10
B) 15
C) 6
D) 4
E) 5
x^2 + y^2 should make you think of these formulas:   (x+y)(x+y) = x^2+y^2+2xy   We already know (x+y) = -4 and x*y = 6   (x+y)(x+y) = (-4)(-4) = x^2+y^2+2*(6)   x^2+y^2 = 16 - 12= 
<gadget id="calculator">16 - 12</gadget>
<output>4</output>
4   Answer : 4
<result>D</result>
If x+y=-4, and x=6/y, what is the value of x^2+y^2?