a-3=a+r

Solution for a-3=a+r equation:

Simplifying
a + -3 = a + r

Reorder the terms:
-3 + a = a + r

Add '-1a' to each side of the equation.
-3 + a + -1a = a + -1a + r

Combine like terms: a + -1a = 0
-3 + 0 = a + -1a + r
-3 = a + -1a + r

Combine like terms: a + -1a = 0
-3 = 0 + r
-3 = r

Solving
-3 = r

Solving for variable 'r'.

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

Add '-1r' to each side of the equation.
-3 + -1r = r + -1r

Combine like terms: r + -1r = 0
-3 + -1r = 0

Add '3' to each side of the equation.
-3 + 3 + -1r = 0 + 3

Combine like terms: -3 + 3 = 0
0 + -1r = 0 + 3
-1r = 0 + 3

Combine like terms: 0 + 3 = 3
-1r = 3

Divide each side by '-1'.
r = -3

Simplifying
r = -3