1+2=y

Solution for 1+2=y equation:

Simplifying
1 + 2 = y

Combine like terms: 1 + 2 = 3
3 = y

Solving
3 = y

Solving for variable 'y'.

Move all terms containing y to the left, all other terms to the right.

Add '-1y' to each side of the equation.
3 + -1y = y + -1y

Combine like terms: y + -1y = 0
3 + -1y = 0

Add '-3' to each side of the equation.
3 + -3 + -1y = 0 + -3

Combine like terms: 3 + -3 = 0
0 + -1y = 0 + -3
-1y = 0 + -3

Combine like terms: 0 + -3 = -3
-1y = -3

Divide each side by '-1'.
y = 3

Simplifying
y = 3