Answer:
-5a + 3 = -8a - 9
1. Change position of „a” to left side, and numbers to right (remember to change symbol [from minus to plus, and from plus to minus]):
-5a + 8a = -9 -3 =
3a = -12 |:3
2. Divide both side by number of „a” to get answer
a = -4
So the answer is -4