.6=.4+x-3.5

Solution for .6=.4+x-3.5 equation:

Simplifying
0.6 = 0.4 + x + -3.5

Reorder the terms:
0.6 = 0.4 + -3.5 + x

Combine like terms: 0.4 + -3.5 = -3.1
0.6 = -3.1 + x

Solving
0.6 = -3.1 + x

Solving for variable 'x'.

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

Add '-1x' to each side of the equation.
0.6 + -1x = -3.1 + x + -1x

Combine like terms: x + -1x = 0
0.6 + -1x = -3.1 + 0
0.6 + -1x = -3.1

Add '-0.6' to each side of the equation.
0.6 + -0.6 + -1x = -3.1 + -0.6

Combine like terms: 0.6 + -0.6 = 0.0
0.0 + -1x = -3.1 + -0.6
-1x = -3.1 + -0.6

Combine like terms: -3.1 + -0.6 = -3.7
-1x = -3.7

Divide each side by '-1'.
x = 3.7

Simplifying
x = 3.7