Question

How do you solve the system of equations algebraically `x=2y-8, 2x-y=-7`?

Answer 1

`(x,y)to(-2,3)`

Explanation:

`x=2y-8to(1)`

`2x-y=-7to(2)`

`"equation "(1)" gives x in terms of y so substitute into "(2)`

`rArr2(2y-8)-y=-7`

`rArr4y-16-y=-7`

`rArr3y=9rArry=3`

`"substitute this value into equation "(1)`

`x=(2xx3)-8=-2`

`"point of intersection "=(-2,3)`
graph{(y-1/2x-4)(y-2x-7)=0 [-10, 10, -5, 5]}