Pls answer i need this ill give you 20 pts

What is the simplified form of 7 √x • 7 √x • 7 √x • 7 √x?

Evaluate 4 a for a = 5 2/3 . express your answer in simplest form.

Problem melissa is her dad build a walkway in their backyard. the walkway will be 54 feet long and 1.5 feet wide. the local hardware store sells tiles which are 1.5 by 1.5 feet and come in boxes of 12. how many boxes of tiles do they need?