-.5-.75=.20(n+3)

Solution for -.5-.75=.20(n+3) equation:

Simplifying
-0.5 + -0.75 = 0.20(n + 3)

Combine like terms: -0.5 + -0.75 = -1.25
-1.25 = 0.20(n + 3)

Reorder the terms:
-1.25 = 0.20(3 + n)
-1.25 = (3 * 0.20 + n * 0.20)
-1.25 = (0.6 + 0.20n)

Solving
-1.25 = 0.6 + 0.20n

Solving for variable 'n'.

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

Add '-0.20n' to each side of the equation.
-1.25 + -0.20n = 0.6 + 0.20n + -0.20n

Combine like terms: 0.20n + -0.20n = 0.00
-1.25 + -0.20n = 0.6 + 0.00
-1.25 + -0.20n = 0.6

Add '1.25' to each side of the equation.
-1.25 + 1.25 + -0.20n = 0.6 + 1.25

Combine like terms: -1.25 + 1.25 = 0.00
0.00 + -0.20n = 0.6 + 1.25
-0.20n = 0.6 + 1.25

Combine like terms: 0.6 + 1.25 = 1.85
-0.20n = 1.85

Divide each side by '-0.20'.
n = -9.25

Simplifying
n = -9.25