Ican do any other question except for this one just because the six is by itself like what do i do with it, can someone ? im trying to get it into the format (y=mx+b) this is the question——> x + 2y + 6 = 0

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?