0.3(2y-12)-0.5(y-20)=3.4

Solution for 0.3(2y-12)-0.5(y-20)=3.4 equation:

Simplifying
0.3(2y + -12) + -0.5(y + -20) = 3.4

Reorder the terms:
0.3(-12 + 2y) + -0.5(y + -20) = 3.4
(-12 * 0.3 + 2y * 0.3) + -0.5(y + -20) = 3.4
(-3.6 + 0.6y) + -0.5(y + -20) = 3.4

Reorder the terms:
-3.6 + 0.6y + -0.5(-20 + y) = 3.4
-3.6 + 0.6y + (-20 * -0.5 + y * -0.5) = 3.4
-3.6 + 0.6y + (10 + -0.5y) = 3.4

Reorder the terms:
-3.6 + 10 + 0.6y + -0.5y = 3.4

Combine like terms: -3.6 + 10 = 6.4
6.4 + 0.6y + -0.5y = 3.4

Combine like terms: 0.6y + -0.5y = 0.1y
6.4 + 0.1y = 3.4

Solving
6.4 + 0.1y = 3.4

Solving for variable 'y'.

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

Add '-6.4' to each side of the equation.
6.4 + -6.4 + 0.1y = 3.4 + -6.4

Combine like terms: 6.4 + -6.4 = 0.0
0.0 + 0.1y = 3.4 + -6.4
0.1y = 3.4 + -6.4

Combine like terms: 3.4 + -6.4 = -3
0.1y = -3

Divide each side by '0.1'.
y = -30

Simplifying
y = -30