PLZ PLZ PLZ PLZ PLZ PLZ PLZ PLZ HELP 15 POINTS A coffee shop sells bags of coffee for a regular price of $7 per bag. John bought some bags and used a coupon for $15 off his entire purchase. After applying the coupon, he paid $20. How many bags of coffee did he buy?

(a) Write an equation to help answer the question above.
Choose the correct form below and fill in the blanks using only 7, 15, and 20.
(The variable x is used to represent the number of bags.)
_x+_=_
or
_x-_=_
(b) Write an expression to help answer the question above.
Choose the correct form below and fill in the blanks using only 7, 15, and 20.
_+_
_
or
_-_
_
(c) How many bags of coffee did John buy?
_bags