A bacteria population has been doubling each day for the last 5 days. It is currently 100,000. What was the bacterial population 5 days ago?

Day 5 = 100,000
100,000/2 = 50,000
Day 4 = 50,000
50,000/2 = 25,000
Day 3 = 25,000
25,000/2 = 12,500
Day 2 = 12,500
12,500/2 = 6,250
Day 1 = 6,250
6,250/2 = 3,125
Day 0 = 3,125

2

1.17+3.99a. you combine the terms with a to create 3.99 and the 1.17 stays because it has no like terms or a variable