Roland; 20+15+16=51, 51÷3= 17
Roland; 17
We divide 3 because it's the total number of grade she got.
Jetta; 16+19+17=52, 52÷3= 17.1
Jetta; 17.1
So, probably Jetta got better grade than Rolanda
1/7-9/7n+6/7
1-9/7n
That is the extended form and is simplified
Hope it helps! :)