83.8k views
3 votes
URGENT DUE BY 1:00 FOR MY FINAL GRADE PLEASE HELP OR I WILL FAIL SEMESTER WILL RATE GOOD THX BLESS YOU!!!!

Andrew earns an allowance of $14 the first week, $17 the next week, $20 the following week, and so on. How much will Andrew earn over the course of 10 weeks?

2 Answers

3 votes
f(x) = 3x + 11
Is the function used to show this.

when you know this, you are able to do the following:
f(10) = 30 + 11 = $41
That would be the allowance of the 10th week.

The question, however wants the total.

This again, can be done like this:
f(1) + f(2) + f(3) + f(4) + f(5) + f(6) + f(7) + f(8) + f(9) + f(10) = $275 :)
14 + 17 + 20 + 23 + 26 + 29 + 32 + 35 + 38 + 41 = $275

Sure there is a better formula, but i couldnt seem to make it, sorry.

HUGE UPDATE: The sum is $275 not 200..


User Yarnabrina
by
7.9k points
3 votes

Answer: $275

Explanation:

Given : Andrew earns an allowance of $14 the first week, $17 the next week, $20 the following week, and so on.

We can see that each week there is his allowance is increasing by $3.

That means his allowance is increasing Arithmetically.

We know that for Arithmetic sequence , the sum of first n terms is given by :-


S_n=(n)/(2)(2a+(n-1)d)

, where a = First term

d= common difference

For the given situation, a = $14 and d=$3

Then, for n= 10 , we have


S_n=(10)/(2)(2(14)+(10-1)3)=(5)(55)=275

Hence, Andrew will earn $275 over the course of 10 weeks.

User Chance Smith
by
8.6k points

No related questions found