0.90x+0.05(12-x)=-0.10(-91)

Solution for 0.90x+0.05(12-x)=-0.10(-91) equation:

Simplifying
0.90x + 0.05(12 + -1x) = -0.10(-91)
0.90x + (12 * 0.05 + -1x * 0.05) = -0.10(-91)
0.90x + (0.6 + -0.05x) = -0.10(-91)

Reorder the terms:
0.6 + 0.90x + -0.05x = -0.10(-91)

Combine like terms: 0.90x + -0.05x = 0.85x
0.6 + 0.85x = -0.10(-91)

Multiply -0.10 * -91
0.6 + 0.85x = 9.1

Solving
0.6 + 0.85x = 9.1

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 + 0.85x = 9.1 + -0.6

Combine like terms: 0.6 + -0.6 = 0.0
0.0 + 0.85x = 9.1 + -0.6
0.85x = 9.1 + -0.6

Combine like terms: 9.1 + -0.6 = 8.5
0.85x = 8.5

Divide each side by '0.85'.
x = 10

Simplifying
x = 10