add the like terms that are on the left, then isolate the variable (a) on the left by dividing both sides by .
2a + 6a = -24
8a = -24 added like terms (2a + 6a)
8a/8 = -24/8 divided both sides by 8
a = -3 simplified (8/8 = 1 and -24/8 = -3)
Answer: -3
