Question

If xy = -3 and (x + y)^2 = 33, what is the value of x^2 + y^2?
(a) 27
(b) 30
(c) 33
(d) 36
(e) 39

Answer 1

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

Answer 2

ok got the answer (a) 27

Answer 3

how did you get that?

Answer 4

i did x^2 + y^2 + 2(-3) = 33 which is x^2 + y^2 -6 =33 and then i soled for x^2 + y^2 which is 27. is that right?

Answer 5

oh wait never mind it's 39 right?

Answer 6

how did you get 27 if you had x^2 + y^2 - 6 = 33

Answer 7

yup 39

Answer 8

yeah i subtracted instead of adding but thanks