Question

How do you solve the following system using substitution?: `y=x-4, y=2x`

Answer 1

`x = -4 , y= -8`

Explanation:

Substitute eq2 in eq1 :
`" "`
`2x = x - 4`
`" "`
`rArr 2x - x = - 4`
`" "`
`rArr x = -4`
`" "`
Substitute the value of `x` in eq2
`" "`
`y = 2x = 2 (-4) = -8`
`" "`
`therefore x = -4 , y = -8`