Answer: B. 
Step-by-step explanation:
The notation to express a dependent variable is given by :-
, where Y is depending variable which is dependent upon x ( independent variable).
The given statement : The distance an airplane travels depends on how much time it spends flying.
Here , Independent variable : Time
Dependent variable : Distance
Then , the notation to express distance (dependent variable) the airplane flies in 20 minutes is given by :-

Answer:
The first answer is 21x+22.
Second answer is 36+3x.
Third answer is 29x+6.
Step-by-step explanation:
I just simplified
100-9(2+6)=100-9(8)=100-72=
so the answer is 28
Answer:
t55=d
Step-by-step explanation:
55 is mph and since t is time t would be multiplied by 55