Answer:
second option
Step-by-step explanation:
x - y= 28
x+y = 56
Answer:

Step-by-step explanation:
By definition, we can write ln instead of log. WHEN??
Whenever the base of the logarithm is the number "e".
Hence, when we have:

We can write it in shortcut as:

Hence, ln x can also be written as 
Fourth answer choice is right.
Answer:
B. 125
Step-by-step explanation:
72 did not return the permission slips.
125-72= 53
So therefore 53 students are going on the field trip.
60*80-10*16 if it's regular area and not surface area