The system of equations has 2 2 2 solutions.
x = 39 2 − 1153 2 , y = 1153 2 + 39 2 x = \frac{39}{2} - \frac{\sqrt{1153}}{2}, y = \frac{\sqrt{1153}}{2} + \frac{39}{2} x = 2 39 − 2 1153 , y = 2 1153 + 2 39 x = 1153 2 + 39 2 , y = 39 2 − 1153 2 x = \frac{\sqrt{1153}}{2} + \frac{39}{2}, y = \frac{39}{2} - \frac{\sqrt{1153}}{2} x = 2 1153 + 2 39 , y = 2 39 − 2 1153
Solve x + y = 39 x + y = 39 x + y = 39 for x x x . x = 39 − y x = 39 - y x = 39 − y Substitute 39 − y 39 - y 39 − y for x x x in x y = 92 x y = 92 x y = 92 and simplify. x y = 92 ( 39 − y ) y = 92 y 2 − 39 y = − 92 y 2 − 39 y + 92 = 0 y = − ( − 39 ) ± ( − 39 ) 2 − 4 ( 1 ) ( 92 ) 2 ( − 39 ) y = 39 2 − 1153 2 , y = 1153 2 + 39 2 \begin{aligned}x y &= 92 \\ \left(39 - y\right) y &= 92 \\ y^{2} - 39 y &= -92 \\y^{2} - 39 y + 92 &= 0 \\ y &= \frac{-(-39) \pm \sqrt{(-39)^{2} - 4(1)(92)}}{2(-39)} \\ y = \frac{39}{2} - \frac{\sqrt{1153}}{2}&, y = \frac{\sqrt{1153}}{2} + \frac{39}{2}\end{aligned} x y ( 39 − y ) y y 2 − 39 y y 2 − 39 y + 92 y y = 2 39 − 2 1153 = 92 = 92 = − 92 = 0 = 2 ( − 39 ) − ( − 39 ) ± ( − 39 ) 2 − 4 ( 1 ) ( 92 ) , y = 2 1153 + 2 39 Substitute 39 2 − 1153 2 \frac{39}{2} - \frac{\sqrt{1153}}{2} 2 39 − 2 1153 into x + y = 39 x + y = 39 x + y = 39 to solve for x x x . x − 1153 2 + 39 2 = 39 x + ( 39 2 − 1153 2 ) = 39 x = 1153 2 + 39 2 \begin{aligned}x - \frac{\sqrt{1153}}{2} + \frac{39}{2} &= 39\\x + \left(\frac{39}{2} - \frac{\sqrt{1153}}{2}\right) &= 39\\x &= \frac{\sqrt{1153}}{2} + \frac{39}{2}\end{aligned} x − 2 1153 + 2 39 x + ( 2 39 − 2 1153 ) x = 39 = 39 = 2 1153 + 2 39 This yields the following solution. x = 1153 2 + 39 2 , y = 39 2 − 1153 2 \begin{aligned}x = \frac{\sqrt{1153}}{2} + \frac{39}{2},\,y = \frac{39}{2} - \frac{\sqrt{1153}}{2}\end{aligned} x = 2 1153 + 2 39 , y = 2 39 − 2 1153 Substitute 1153 2 + 39 2 \frac{\sqrt{1153}}{2} + \frac{39}{2} 2 1153 + 2 39 into x + y = 39 x + y = 39 x + y = 39 to solve for x x x . x + 1153 2 + 39 2 = 39 x + ( 1153 2 + 39 2 ) = 39 x = 39 2 − 1153 2 \begin{aligned}x + \frac{\sqrt{1153}}{2} + \frac{39}{2} &= 39\\x + \left(\frac{\sqrt{1153}}{2} + \frac{39}{2}\right) &= 39\\x &= \frac{39}{2} - \frac{\sqrt{1153}}{2}\end{aligned} x + 2 1153 + 2 39 x + ( 2 1153 + 2 39 ) x = 39 = 39 = 2 39 − 2 1153 This yields the following solution. x = 39 2 − 1153 2 , y = 1153 2 + 39 2 \begin{aligned}x = \frac{39}{2} - \frac{\sqrt{1153}}{2},\,y = \frac{\sqrt{1153}}{2} + \frac{39}{2}\end{aligned} x = 2 39 − 2 1153 , y = 2 1153 + 2 39