.6(X+100)+.8X=109

Solution for .6(X+100)+.8X=109 equation:

Simplifying
0.6(X + 100) + 0.8X = 109

Reorder the terms:
0.6(100 + X) + 0.8X = 109
(100 * 0.6 + X * 0.6) + 0.8X = 109
(60 + 0.6X) + 0.8X = 109

Combine like terms: 0.6X + 0.8X = 1.4X
60 + 1.4X = 109

Solving
60 + 1.4X = 109

Solving for variable 'X'.

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

Add '-60' to each side of the equation.
60 + -60 + 1.4X = 109 + -60

Combine like terms: 60 + -60 = 0
0 + 1.4X = 109 + -60
1.4X = 109 + -60

Combine like terms: 109 + -60 = 49
1.4X = 49

Divide each side by '1.4'.
X = 35

Simplifying
X = 35