The average mileage covered per day is = number of miles / number of days.
The average mileage covered per day is =(x+y+z)/3
Doing (7x÷7) I think equals 1
Answer
(9-j)-3
Step-by-step explanation:
ANSWER
The correct answer is D.

EXPLANATION
The given expression is

The symbol means summation.
So we need to substitute

into the formula and add all to get,

We simplify to obtain,

The correct answer is D