Step 1) Solve the first equation for y:
x + y - color(red)(x) = 3 - color(red)(x)
x - color(red)(x) + y = 3 - x
0 + y = 3 - x
y = 3 - x
Step 2) Substitute 3 - x for y in the second equation and solve for x:
3x + y = 5 becomes:
3x + 3 - x = 5
3x - x + 3 = 5
2x + 3 = 5
2x + 3 - color(red)(3) = 5 - color(red)(3)
2x + 0 = 2
2x = 2
(2x)/color(red)(2) = 2/color(red)(2)
(color(red)(cancel(color(black)(2)))x)/cancel(color(red)(2)) = 1
x = 1
Step 3) Substitute 1 for x in the solution to the first equation at the end of Step 1 and calculate y:
y = 3 - x becomes:
y = 3 - 1
y = 2
The solution is: x = 1 and y = 2 or (1, 2)
