Answer:
13+x
Step-by-step explanation:
all you have to do is 9+4 which is 13 and leave the +x so you get 13+x as your answer
Answer:
They are equal
Step-by-step explanation:
Using the rule of exponents
= 
Given
=
= 
The exponents of both expression are 8 and therefore equal
15$ I believe, as we can disregard the two original books (they have been payed for) leaving her to buy 1 book and having seven dollars, however if she needs $8 more you simply need to add 8+7.