The GCF (Greatest Common Factor) is 6a.
We can get the answer to this equation by solving for the variable (r).
7.4 - 9 - 2r = 18
We want to get r on one side, so we want to push everything else to the other side.
-2r = 18 - 7.4 + 9
-2r = 19.6
2r = -19.6
r = -9.8
