.40+.05(4-x)=0.10(9)

Solution for .40+.05(4-x)=0.10(9) equation:

Simplifying
0.40 + 0.05(4 + -1x) = 0.10(9)
0.40 + (4 * 0.05 + -1x * 0.05) = 0.10(9)
0.40 + (0.2 + -0.05x) = 0.10(9)

Combine like terms: 0.40 + 0.2 = 0.6
0.6 + -0.05x = 0.10(9)

Multiply 0.10 * 9
0.6 + -0.05x = 0.9

Solving
0.6 + -0.05x = 0.9

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 + -0.05x = 0.9 + -0.6

Combine like terms: 0.6 + -0.6 = 0.0
0.0 + -0.05x = 0.9 + -0.6
-0.05x = 0.9 + -0.6

Combine like terms: 0.9 + -0.6 = 0.3
-0.05x = 0.3

Divide each side by '-0.05'.
x = -6

Simplifying
x = -6