Please help meee I don’t understand

There are 15 plates and each plate is either 7 or 12 inches diameter. which systems of equations do you use to find the number of 7 inch plates, x and 12 inch plates, y

Afamily of five rents a kayak and splits the total time, k, equally. each family member spent less than 25 minutes kayaking. which values can be used to complete the math sentence below so that it accurately represents the situation? intro done

26) -2(7x) = (-2 • 7) x a. associative property of addition b. associative property of multiplication c. commutative property of multiplication d. commutative property of addition