All the steps arranged in the attachment!
You applied the rule improperly. When dividing exponents, you subtract the exponent of the denominator <em>from</em> the exponent of the numerator, not the other way around. The exponent you should have gotten was 
Answer:
-150
Step-by-step explanation:
Multiply & Divide left to right

Once again Multiply & Divide

Add & Subtract
Final Answer: 
How many books has she read so far? She's been doing this for 7 months, so so far she's read:
7*3=21
how many does she still need to read?
30-21=9
so she needs to read 9 more books. With 3 books a month, this means:
9/3=3
so she needs to read 9 more books, which will take her 3 months!
Answer:

Step-by-step explanation:

Hope this helped!
<h2>~AnonymousHelper1807</h2>