Move all terms not containing a to the right side of the equation.
Add 4 to both sides of the equation.
Add 23 and 4.
Divide each term by 3 and simplify.
Divide each term in 3a=27 by 3.
Cancel the common factor of 3.
Cancel the common factor.
Divide a by 1.
Divide 27 by 3.
Solve for a 3a-4=23