X=y-1 y = (4-2x) solve by substition

Since you have an equation equal to both x and y, you can either substitute the equation equal to x for x or the equation equal to y for y.

x=y-1

y=4-2x

I would substitute the y in using 4-2x

x = (4-2x) - 1

x=3-2x

3x=3

x=1

Then plug in x and solve for y

1=y-1

2=y