Question

What is the substitution method for 2x=8 and x+y=2

Answer 1

`x=4,\ y=-2`

Explanation:

You can use substitution method in two ways.

1 way: From the first equation
`2x=8` you can express x by dividing the whole equation by 2:

`x=4`

and substitute this x-value into the second equation:

`4+y=2,\\y=2-4,\\y=-2.`

2 way: From the second equation you can express x:

`x=2-y`

and substitute it into the first one:

`2(2-y)=8,\\4-2y=8,\\-2y=8-4,\\-2y=4,\\2y=-4,\\y=-2.`