Ben rents a car for one day. the charge is $20 plus the $.12 per mile. he wants to spend exactly $80. how many miles can he drive?

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie

Tim's phone service charges $26.39 plus an additional $0.21 for each text message sent per month. if tim's phone bill was $31.64, which equation could be used to find how many text messages, x, tim sent last month?

Which value of m will create a system of parallel lines with no solution? y = mx - 6 8x - 4y = 12