\( \begin{eqnarray} x^3 + y^2 + x^2 y + xy & = & 91 \\ x^4 + 2x^2 y + y^2 &= & 169 \\ \end{eqnarray} \)
If positive integers x,y satisfy the system of equations above, what is the value of x+y?
+36915 The first one factors to
(x+y)(x^2+y) = 91
the second one factors to (x^2+y)^2 = 169 sooooo x^2 + y = 13 sub into the first equation above
(x+y)(13) = 91
x+y = 91/13 = 7
