<u>The error is that they had placed the numbers in the wrong placeholder.</u> Remember that the Distance formula is
.
<em><u>Correct Work:</u></em>

Answer:
I think jillian will have to run 10 miles
Step-by-step explanation:
2 miles = 100 calories
in order to burn 500 calories
2 miles = 100 calories burned
4 miles = 200 calories burned
6 miles = 300 calories burned
8 miles = 400 calories burned
10 miles = 500 calories burned
-2a+2=22
3(a+4)-5(a-2)=22
3a+12-5a-10=22
-2a+12-10=22
-2a+2=22