0.90x+0.05(12-x)=0.10(-28)

Solution for 0.90x+0.05(12-x)=0.10(-28) equation:

Simplifying
0.90x + 0.05(12 + -1x) = 0.10(-28)
0.90x + (12 * 0.05 + -1x * 0.05) = 0.10(-28)
0.90x + (0.6 + -0.05x) = 0.10(-28)

Reorder the terms:
0.6 + 0.90x + -0.05x = 0.10(-28)

Combine like terms: 0.90x + -0.05x = 0.85x
0.6 + 0.85x = 0.10(-28)

Multiply 0.10 * -28
0.6 + 0.85x = -2.8

Solving
0.6 + 0.85x = -2.8

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 = -2.8 + -0.6

Combine like terms: 0.6 + -0.6 = 0.0
0.0 + 0.85x = -2.8 + -0.6
0.85x = -2.8 + -0.6

Combine like terms: -2.8 + -0.6 = -3.4
0.85x = -3.4

Divide each side by '0.85'.
x = -4

Simplifying
x = -4