get all variables (in this case, "a") on one side by adding "2a" to both. this cancels the "-2a". then, combine like terms. also move "-3" to the other side, by adding "3". finally, divide the "6" and "a" by "9" to get variable alone. therefore, "a = 2/3".
7a-3=3-2a
+2a +2a
9a-3=3
+3 +3
9a=6
a=2/3
