A sequence can be generated by using an = 4 a(n-1),where a1 = 6 and n is a while number greater than 1 what are the first four terms in the sequence

Jack lives on a farm and has a large backyard. the area of his rectangular backyard is of a square mile. if the width of the yard is of a mile, what fraction of a mile is the length of the rectangular backyard?

If y varies directly as x2 and y=6 when x=6, find the constant of variation.

Me. i can't figure out this question. give an explanation too. .