78.9=A-15

Solution for 78.9=A-15 equation:

Simplifying
78.9 = A + -15

Reorder the terms:
78.9 = -15 + A

Solving
78.9 = -15 + 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.
78.9 + -1A = -15 + A + -1A

Combine like terms: A + -1A = 0
78.9 + -1A = -15 + 0
78.9 + -1A = -15

Add '-78.9' to each side of the equation.
78.9 + -78.9 + -1A = -15 + -78.9

Combine like terms: 78.9 + -78.9 = 0.0
0.0 + -1A = -15 + -78.9
-1A = -15 + -78.9

Combine like terms: -15 + -78.9 = -93.9
-1A = -93.9

Divide each side by '-1'.
A = 93.9

Simplifying
A = 93.9