A culture of a certain bacteria doubles every hour . At 9:00 a.m. there were already were already 120 bacteria. Which equation represents the number of bacteria. , n, at 8:00 AM? How many bacteria’s were there?

Answer 1

Let's assume that n represents the number of hours since 8:00 a.m.

Since the bacteria doubles every hour, we can use the equation:
n = 9 - x

Where x represents the number of hours between 8:00 a.m. and 9:00 a.m.

To find the value of x, we subtract 8:00 a.m. from 9:00 a.m.
9:00 a.m. - 8:00 a.m. = 1 hour

Since there was 1 hour between 8:00 a.m. and 9:00 a.m., we substitute x = 1 in the equation:
n = 9 - 1
n = 8

The equation that represents the number of bacteria at 8:00 a.m. is n = 8.

Since n = 8, the number of bacteria at 8:00 a.m. is 8.