Lets look at the information we have:-
Daniel ran 26 miles LESS than Amanda.
Daniel ran 5 miles.
5 + 26 = Amount of miles Amanda ran.
5 + 26 = 31
Amanda ran 31 miles last week.
CHECK OUR WORK:-
31 - 5 = 26
We were RIGHT!!!
So, Amanda ran 31 miles last week.
Hope i helped ya!!