4-3.1=y

Solution for 4-3.1=y equation:

Simplifying
4 + -3.1 = y

Combine like terms: 4 + -3.1 = 0.9
0.9 = y

Solving
0.9 = 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.
0.9 + -1y = y + -1y

Combine like terms: y + -1y = 0
0.9 + -1y = 0

Add '-0.9' to each side of the equation.
0.9 + -0.9 + -1y = 0 + -0.9

Combine like terms: 0.9 + -0.9 = 0.0
0.0 + -1y = 0 + -0.9
-1y = 0 + -0.9

Combine like terms: 0 + -0.9 = -0.9
-1y = -0.9

Divide each side by '-1'.
y = 0.9

Simplifying
y = 0.9