.4(y-9)=.3(y+4)

Solution for .4(y-9)=.3(y+4) equation:

Simplifying
0.4(y + -9) = 0.3(y + 4)

Reorder the terms:
0.4(-9 + y) = 0.3(y + 4)
(-9 * 0.4 + y * 0.4) = 0.3(y + 4)
(-3.6 + 0.4y) = 0.3(y + 4)

Reorder the terms:
-3.6 + 0.4y = 0.3(4 + y)
-3.6 + 0.4y = (4 * 0.3 + y * 0.3)
-3.6 + 0.4y = (1.2 + 0.3y)

Solving
-3.6 + 0.4y = 1.2 + 0.3y

Solving for variable 'y'.

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

Add '-0.3y' to each side of the equation.
-3.6 + 0.4y + -0.3y = 1.2 + 0.3y + -0.3y

Combine like terms: 0.4y + -0.3y = 0.1y
-3.6 + 0.1y = 1.2 + 0.3y + -0.3y

Combine like terms: 0.3y + -0.3y = 0.0
-3.6 + 0.1y = 1.2 + 0.0
-3.6 + 0.1y = 1.2

Add '3.6' to each side of the equation.
-3.6 + 3.6 + 0.1y = 1.2 + 3.6

Combine like terms: -3.6 + 3.6 = 0.0
0.0 + 0.1y = 1.2 + 3.6
0.1y = 1.2 + 3.6

Combine like terms: 1.2 + 3.6 = 4.8
0.1y = 4.8

Divide each side by '0.1'.
y = 48

Simplifying
y = 48