X + a/b = m/n x + a/b - a/b = m/n - a/b x = m/n - a/b x = (b/b) (m/n) - (n/n) (a/b) x = bm/bn - an/bn x = bm - an/bn what type of number x must be for the sum to be rational?

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?