Which expression uses the commutative property of addition and the associative property of multiplication to rewrite the expression ?

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Ok a point t on a segment with endpoints d(1, 4) and f(7, 1) partitions the segment in a 2: 1 ratio. find t. you must show all work to receive credit.

Tom can paint the fence in 12 hours, but if he works together with a friend they can finish the job in 8 hours. how long would it take for his friend to paint this fence alone?