At one farmer's market per bag. which explains how to find the better buy? t, bananas cost $0.80 per pound. at another farmer's market, bananas are sold in 5-pound bags for $4.50

Can someone me out here number 4 plz

Kayla and alberto are selling fruit for a school fundraiser. customers can buy small boxes of grapefruit and large boxes of grapefruit. kayla sold 3 small boxes of grapefruit and 1 large box of grapefruit for a total of $65. alberto sold 1 small box of grapefruit and 1 large box of grapefruit for a total of $55. what is the cost each of one small box of grapefruit and one large box of grapefruit?

Check all that apply. f is a function. f is a one-to-one function. c is a function. c is a one-to-one function.