Well you have your y so you just put y with four so it would be 3x +4 (4)+8= 0 then you multiple 4 times 4 and get 24 then you slove it like a equation
D) 150 miles ~ because when you multiply 150 miles by 30 cents every mile you get 45 which you add to the $20 a day fee you reach $65 which is equal to the $65 of Agency A