Please someone help me with this I need this assignment done by today

An 18% discount on a watch saved a shopper $72. find the price of the watch before the discount

Which equation represents a direct linear variationa. y=x2b. y=2/5xc. y=1/xd. y=x+3

Determine if the solution set for the system of equations shown is the empty set, contains one point or is infinite. x + y = 5 x + y = 7 {} 1 solution infinite