y = 12 + x
y + x = 74
Since we have a value for y, we can plug it into the second equation
12 + x + x = 74
Subtract 12 from both sides.
x + x = 62
Combine like terms.
2x = 62
Divide both sides by 2.
x = 31
Now that we have a value of x, we can plug it into the original equation to get a value for y.
y = 12 + 31
y = 43