Answer:
is b
Step-by-step explanation: because x-4y
Answer:

Step-by-step explanation:
Using the rule of exponents
⇔
, then
=
= 
Answer:
28/21
Step-by-step explanation:
You would do 13-(-15) to find the numerator which is 28. Then you would do 8-(-13) to get the denominator which is 21.