8.5-4=a

Solution for 8.5-4=a equation:

Simplifying
8.5 + -4 = a

Combine like terms: 8.5 + -4 = 4.5
4.5 = a

Solving
4.5 = a

Solving for variable 'a'.

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

Add '-1a' to each side of the equation.
4.5 + -1a = a + -1a

Combine like terms: a + -1a = 0
4.5 + -1a = 0

Add '-4.5' to each side of the equation.
4.5 + -4.5 + -1a = 0 + -4.5

Combine like terms: 4.5 + -4.5 = 0.0
0.0 + -1a = 0 + -4.5
-1a = 0 + -4.5

Combine like terms: 0 + -4.5 = -4.5
-1a = -4.5

Divide each side by '-1'.
a = 4.5

Simplifying
a = 4.5