Answer:
15a+12ac+6ab
Step-by-step explanation:
3a(5 + 4c + 2b)
5*3a = 15a
4c*3a = 12ac
2b*3a = 6ab
Year 1: 10
Year 2: 20
Year 3: 40
Year 4: 80
Year 6: 160
Year 7: 320
Year 8: 640
Year 9: 1280
Year 10: 2560
