Question

How do you solve by substitution `y=x+3` and `5x+y=9`?

Answer 1

`x=1`
`y=4`

Explanation:

`y=x+3` --- (1)
`5x+y=9` --- (2)

Sub (1) into (2)

`5x+x+3=9`

`6x=6`

`x=1` --- (3)

Sub (3) into (1)

`y=1+3`

`y=4`