Answer:
b=-3
Step-by-step explanation:
-7b=21
-7b/-7=21/-7
b=-3
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.
Answer:
the number I would to divide the numerator and denominator is 5/5
Answer:

Step-by-step explanation:

Expand brackets.


Apply radical rule : 

