Question

Solve the following system of equations using substitution.

1)y = 3x - 5


2)5x - 4y = -3

Answer 1

To solve system of equations by substitution, we are going to use the first equation to substitute into the second equation wherever you see y.

`5x - 4y = -3`

`5x - 4(3x-5) = -3`

`5x -12x+20=-3`

`-20`
`-20`

_______________

`5x-12x=-23`

`-7x=-23`

___ ____

`-7`
`-7`

`x=3.29` (rounded)

Next, substitute x = 3.29 into the first equation, or to any equation you'd like, to find y.

`y = 3x-5`

`y = 3(3.29)-5`

`y = 9.87-5`

`y = 4.87`

So, your final answer would be (3.29, 4.87).