Answer:
a)5
b)17
c) ?

Step-by-step explanation:
The answer to you’re question is 5 1/2 multiplied by 5 1/3. I submitted a photo showing how to put the answer.
Answer:
part A:d=5.4-3.1
Part B:t=4.9+3.1
Part C:If ted walks 5.4 kilometers,then david walks 2.3 kilometers,If david walks 4.9 kilometers,then ted walks 8 kilometers.
Want it exact? Here it is:499.243083(got it from my calculator), if rounded, then here it is:500