Find the solution set for the system of equations
{ 6
{ ---------------- + 2x – y = 13
{ x+y
{
{ 16
{ ---------------- + 2y – 4x = -12
{ x+y
2x^2 + xy - 13x + 6=y^2 + 13y..........(1)
2 x^2 + xy - 6 x =y^2 + 6y + 8..........(2)
Subtract (2) from (1) and we get:
x = 2 - y and subbing this in (1) above we get:
y = -2 and subbing this in (2) above we get:
x = 4
6
---------------- + 2x – y = 13 (1)
x + y
16 8
---------------- + 2y – 4x = -12 divide this through by 2 ⇒ ________ + y - 2x = -6 (2)
x + y x + y
Rearrange (2) as 8 + 6 = 2x - y
____
x + y
Sub this into (1)
6 + 8 + 6 = 13
___ ___
x + y x + y
14 = 7
___
x + y
14 = 7 ( x + y )
2 = x + y (3)
Sub (3) into (1)
6
__ + 2x - y = 13
2
3 + 2x - y = 13
2x - y = 10
y = 2x - 10 (4)
Sub (4) into (3)
2 = x + 2x - 10
12 = 3x
4 = x
And using (4)
y = 2(4) - 10 = -2