Answer:
I think like 21
Step-by-step explanation:
i think it correct but if it not it okay but alaest I try my best on it
Her fastest change in elevation was -200 feet in 10 minutes. She was going at a rate of 20 fpm (feet per minute) compared to 15 fpm.
Answer:
and 
Step-by-step explanation:
Options

Required
Select the unit rates
Unit rate involve two items where the first item being measured can be any positive number, but the second item must be measured in units (i.e. 1)
For clarity:
If
represents unit rate, then 
Having said that:
Only
and
satisfy the condition of unit rates; others are not because they have a denominator other than 1
Answer:
a)=+2 b)=1
Step-by-step explanation:
A positive plus a negative is equal to a positive a
Doing this so I can ask sorry