What property is 150 + 214 + 89 equals 214 plus 89 plus 150

What properties allow transformation to be used as a problem solving tool

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?

Two years ago a man was six times as old as his daughter. in 18 years he will be twice as old as his daughter. determine their present ages.