Can someone give me the equation on this and or how to right it A number is 7 more than 5 times another number and their difference is 78 Find the numbers

Acomputer store buys a computer system at a cost of $370.80. the selling price was first at $ 618, but then the store advertised a 20 % markdown on the system. answer parts a and b. a. find the current sale price.

You buy a veido game for $60 and the sales tax is 8% what is the total cost for the game including the sales tax

Ofof is a ? a. (1, 2), (1,-2), (3, 2), (3, 4) b. (1,6), (2, ,9), (0,5) c. (0, 2), (2,3), (0, -2), (4,1) d. (2, 4), (0, 2), (2, - 4), (5,3)