0.8x-0.4(3-x)=4.2

Solution for 0.8x-0.4(3-x)=4.2 equation:

Simplifying
0.8x + -0.4(3 + -1x) = 4.2
0.8x + (3 * -0.4 + -1x * -0.4) = 4.2
0.8x + (-1.2 + 0.4x) = 4.2

Reorder the terms:
-1.2 + 0.8x + 0.4x = 4.2

Combine like terms: 0.8x + 0.4x = 1.2x
-1.2 + 1.2x = 4.2

Solving
-1.2 + 1.2x = 4.2

Solving for variable 'x'.

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

Add '1.2' to each side of the equation.
-1.2 + 1.2 + 1.2x = 4.2 + 1.2

Combine like terms: -1.2 + 1.2 = 0.0
0.0 + 1.2x = 4.2 + 1.2
1.2x = 4.2 + 1.2

Combine like terms: 4.2 + 1.2 = 5.4
1.2x = 5.4

Divide each side by '1.2'.
x = 4.5

Simplifying
x = 4.5