Answer:
![E(n)=75000 * 2^n](https://img.qammunity.org/2019/formulas/mathematics/middle-school/qodffjdyyra3zp9i9hk39ntinf3uwrt5ak.png)
Explanation:
We are given that she earned $75000 for the first book.
We are also given that her cumulative earnings double with each sequel that she writes.
Let she has written n sequel's
Now since we are given that her cumulative earnings double with each sequel
So, her initial earning will be
![2^n times](https://img.qammunity.org/2019/formulas/mathematics/middle-school/x67k42yha1dut7vlacav6ta4ykr5gwix9t.png)
So, her earning will be :
![75000 * 2^n](https://img.qammunity.org/2019/formulas/mathematics/middle-school/695zk31506u10cfdoypu5ds1wigtit5ozu.png)
Now we are given that cumulative earnings is denoted by E(n)
So, the function becomes :
![E(n)=75000 * 2^n](https://img.qammunity.org/2019/formulas/mathematics/middle-school/qodffjdyyra3zp9i9hk39ntinf3uwrt5ak.png)
Hence a function that gives Mapiyas cumulative earnings E(n), in dollars when she has written n sequel's is
![E(n)=75000 * 2^n](https://img.qammunity.org/2019/formulas/mathematics/middle-school/qodffjdyyra3zp9i9hk39ntinf3uwrt5ak.png)