Move all terms not containing a to the right side of the equation.
Add 5 to both sides of the equation.
Add -77 and 5.
Divide each term by 18 and simplify.
Divide each term in 18a=-72 by 18.
Cancel the common factor of 18.
Cancel the common factor.
Divide a by 1.
Divide -72 by 18.
Solve for a -5+18a=-77