Question

How do you solve the system `y = 5x - 7` and `-4 + y = -1` by substitution?

Answer 1

`y = 5x - 7` ..........equation `(1)`

`-4 + y =-1` ......equation `(2)`

substituting equation `(1)` in equation `(2)`

`-4 + y =-1`
`-4 + (5x -7)= -1`
`5x -11= -1`
`5x = 10`
`x = 2`

substituting the value of `x` in equation `(1)`
`y = 5x - 7 = 5.(2) -7`
`y = 10 -7 = 3`

The solutions for the system of equations are :
`color(blue)x=2`
`color(blue)y=3`