How many three letter permutations can be formed from the first five letters of the alphabet?

It took alice 5 5/6 hours to drive to her grandparents' house for . on the way home, she ran into traffic and it took her 7 3/8 hours. how much longer did the return trip take? write your answer as a proper fraction or mixed number in simplest form. the trip home took __hours longer. ?

2/3(-6y+9x) expand each expression using the distributive property

Which geometric principle is used to justify the construction below?