0.85x+0.05(12-x)=0.10(-42)

Solution for 0.85x+0.05(12-x)=0.10(-42) equation:

Simplifying
0.85x + 0.05(12 + -1x) = 0.10(-42)
0.85x + (12 * 0.05 + -1x * 0.05) = 0.10(-42)
0.85x + (0.6 + -0.05x) = 0.10(-42)

Reorder the terms:
0.6 + 0.85x + -0.05x = 0.10(-42)

Combine like terms: 0.85x + -0.05x = 0.8x
0.6 + 0.8x = 0.10(-42)

Multiply 0.10 * -42
0.6 + 0.8x = -4.2

Solving
0.6 + 0.8x = -4.2

Solving for variable 'x'.

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

Add '-0.6' to each side of the equation.
0.6 + -0.6 + 0.8x = -4.2 + -0.6

Combine like terms: 0.6 + -0.6 = 0.0
0.0 + 0.8x = -4.2 + -0.6
0.8x = -4.2 + -0.6

Combine like terms: -4.2 + -0.6 = -4.8
0.8x = -4.8

Divide each side by '0.8'.
x = -6

Simplifying
x = -6