Question

How do you solve `2x-y=3` and `x+2y=24` using substitution?

Answer 1

`2x - y = 3`
`x + 2y = 24`

Substitution is a method for solving algebraic equations by finding the value of a variable in terms of other variables and substituting that value into existing equations.
`x = 24 - 2y`

Substituting `24 - 2y` for `x` in the first equation:

`2(24-2y) - y = 3`
`48 -4y - y = 3`
`5y = 48-3`
`5y =45`
`y = 9`

Substituting `9` for `y` in the second equation:
`x + 2*9 = 24`
`x = 24 - 18`
`x = 6`

Answer 2

`x=6` and `y=9`.

Explanation:

`2x-y=3" " " "(1)`
`x+2y=24" " " "(2)`

From eqn `(2)`

`x=24-2y" " " "(3)`

Sub eqn `(3)` into eqn `(1)`

`2(24-2y)-y=3`

`48-4y-y=3`

`45=5y`

`y=9`

Sub `y=9` into eqn `(2)`

`x=24-2(9)`

`x=6`