Please help me I struggle with these

Look at the following graph of the given equation. determine whether the equation is a function. explain why or why not.

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?

The paint recipe also calls for 1/4 cup of food coloring. tyler says mrs. mcglashan will also need 6 cups of food coloring. do u agree or disagree? explain.