A woman made $45,000 during the first year of her new job at city hall. Each year she received a 10% raise. Find her total earnings during the first nine years on the job.

first year she made 45000

after two years she had 45000 + 45000(1.2)
after tree years she had 45000 + 45000(1.1)^2
...

This is a geometric series where
a = 45000
r = 1.1
n = 9

Now use your formula

45k

45(1+.1)
45(1+.1)^2
and so on. Isnt this a geometric series?

Sum a(1+.1)^n where n goes from 0 to 9

http://en.wikipedia.org/wiki/Geometric_series

To find the woman's total earnings during the first nine years on the job, you can calculate the sum of her earnings for each year.

In the first year, she earned $45,000.
In the second year, she received a 10% raise, so her salary increased by 10% of $45,000, which is $4,500. Her salary for the second year would be $45,000 + $4,500 = $49,500.
In the third year, her salary would be increased again by 10% of $49,500, which is $4,950. Her salary for the third year would be $49,500 + $4,950 = $54,450.
You can continue this pattern of calculating the salary for each subsequent year until you reach the ninth year.

Alternatively, you can use a formula to calculate the total earnings. Since the raises are based on a percentage, you can use the formula for the sum of an arithmetic series:

Total earnings = (Initial salary + Final salary) * Number of years / 2

In this case, the initial salary is $45,000, the final salary is the salary in the ninth year (calculated using the raise pattern), and the number of years is 9.

Let's calculate the total earnings.