0.15(x+40)-0.04(x-30)=6.1

Solution for 0.15(x+40)-0.04(x-30)=6.1 equation:

Simplifying
0.15(x + 40) + -0.04(x + -30) = 6.1

Reorder the terms:
0.15(40 + x) + -0.04(x + -30) = 6.1
(40 * 0.15 + x * 0.15) + -0.04(x + -30) = 6.1
(6 + 0.15x) + -0.04(x + -30) = 6.1

Reorder the terms:
6 + 0.15x + -0.04(-30 + x) = 6.1
6 + 0.15x + (-30 * -0.04 + x * -0.04) = 6.1
6 + 0.15x + (1.2 + -0.04x) = 6.1

Reorder the terms:
6 + 1.2 + 0.15x + -0.04x = 6.1

Combine like terms: 6 + 1.2 = 7.2
7.2 + 0.15x + -0.04x = 6.1

Combine like terms: 0.15x + -0.04x = 0.11x
7.2 + 0.11x = 6.1

Solving
7.2 + 0.11x = 6.1

Solving for variable 'x'.

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

Add '-7.2' to each side of the equation.
7.2 + -7.2 + 0.11x = 6.1 + -7.2

Combine like terms: 7.2 + -7.2 = 0.0
0.0 + 0.11x = 6.1 + -7.2
0.11x = 6.1 + -7.2

Combine like terms: 6.1 + -7.2 = -1.1
0.11x = -1.1

Divide each side by '0.11'.
x = -10

Simplifying
x = -10