Solve using the substitution method.?

y = 4 - 2(y - 1)
y = 4 - 2y + 2
3y = 6
y = 2
x = 1

I will solve for y using x's answer.

Y = 4 - 2 (Y-1) because X = y-1
Y = 4 - 2Y + 2 combine like terms 4 and +2 = 6
Y = 6 - 2Y add 2Y to both sides
3y = 6 divide both sides by 3
y = 2

solve for x
x=y-1
x=2-1
x-1

When you see a question like this, you just need to play with it. This one is simple because you are given just 2 variables, and they are both clearly laid out for you.

So, you take x=y-1 and put it into the equation for y=4-2x, for the value of x. So it will now be y = 4-2(y-1). Then solve for y. (y=2).

Now, you can either do the same thing by placing your equation for y into the equation for x (x=4-2x-1), or, you can simply put in the value you got for y into the equation for x. That is, x = y-1 = 2-1 = 1

x=4-2x-1
x+2x=3
3x=3
x=1

y=4-2(1)
y=4-2
y=2

y = 4 - 2x
y = 4 - 2(y-1)
y = 4 - 2y + 2
3y = 6
y = 2

x=y-1
x = 2-1
x = 1

x = 1, y =2