Xy-x^2= -20 x-2y=3 What is x and y?

1 Answer
May 14, 2018

Assuming you meant
xy-x^2= -20xyx2=20
x-2y=3x2y=3
solutions are:
(5,1)(-4,-7/2)(5,1)(4,72)

Explanation:

equation 1
xy-x^2= -20xyx2=20

rearrange
0=x^2-xy-200=x2xy20

use cross method
0=(x-5)(x+4)0=(x5)(x+4)
:.x=5,x=-4

substitute into equation 2
x-2y=3

if x = 5:
5-2y=3
5-3=2y
2=2y
y=1

if x = -4:
-4-2y=3
-4-3=2y
-7=2y
y=-7/2

solutions:
(5,1)(-4,-7/2)