Answer:
8a-36 is the answer.
Step-by-step explanation:
=a+3a-4(9-a)
=a+3a-36+4a
=4a+4a-36
=8a-36
Hope it will help ^_^
8a - 36
a + 3a - 4(9-a)
4a - 4(9-a)
4a- 36 - 4a
