Solve system of equations

first one : x - y = -1
second one : 4x - 2y = 2

x - y = -1
4x - 2y = 2

-2(x - y = -1)
-2x+2y=2

-2x+2y=2 + 4x - 2y = 2

2x=4
x=2

2-y=-1
-y=-3
y=3

So...
x=2 & y=3
In solution set: {2,3}

Solve for x in terms of y in the first equation
x-y = -1
x = y-1
Substitute this value of x into the other equation.
4(y-1)-2y = 2
4y-4-2y = 2
2y - 4 = 2
2y = 6
y=3
Plug this back into the first equation to find x.
x-3=-1
x=2
So the solution is y=3 and x=2 or (2,3)...whichever form you need.

simplify the first one:
x - y = -1
x = y - 1

substitute (y - 1) for x into the second equation:

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

plug 3 for y into the first equation

x - y = -1
x - 3 = -1
x = 2

(x, y) = (2, 3)