Question

When the expression x-1 is substituted into the first equation for y, what is the resulting equation when given `3x-y=2, y=x-1`?

Answer 1

`x=3/2`
Every step shown. As you become more confident with this type of question you will start to jump steps and become much faster at solving them.

Explanation:

Given:

`" "y=x-1" "...................Equation(1)`
`3x-y=2" "....................Equation(2)`
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Using equation(1) substitute for `y` in equation(2)

`color(green)(3xcolor(red)(-y)=2" "->" "3xcolor(red)(-(x-1))=2`

`3x-x+1=2`

but `3x-x=2x`

`2x-1=2`

Add 1 to both sides

`2x-1+1=2+1`

`2x+0=3`

`2x=3`

Divide both sides by 2

`2/2xx x=3/2`

But `2/2=1`

`x=3/2`