Find a direct relationship between x and y. x=t-7 and y=t^2+3t

Scarlet bought three pairs of sunglasses and two shirts for $81 and paula bought one pair of sunglasses and five shirts for $105 what is the cost of one pair of sunglasses and one shirt?

What is the domain of the given function? {(3,-2), (6, 1), (-1, 4), (5,9), (-4, 0); o {x | x= -4,-1, 3, 5, 6} o {yl y = -2,0, 1,4,9} o {x|x = -4,-2, -1,0, 1, 3, 4, 5, 6, 9} o y y = 4,-2, -1, 0, 1, 3, 4, 5, 6, 9}

Sam opened a money-market account that pays 3% simple interest. he started the account with $7,000 and made no further deposits. when he closed the account, he had earned $420 in interest. how long did he keep his account open?