PLEASE PLEASE PLEASE HELP ME

Which of these is and example of a literal equation? a) 6+30=6^2 b)3x-4y c)12=9+3x d)ax-by=k

The parabola x= √y-9 opens: a.)up b.)down c.)right d.)left

Julie goes to the sports store and spends $40.50 before tax. she buys a pair of shorts for $21.75 and 3 pairs of socks that each cost the same amount. how much does each pair of socks cost? $$