1/2 + 1/3 - 1/4 = I don't know

Explain how you can use the associative property to evaluate (7x50)x4.

Liz is shipping a package to her friend.the maximum weight of a medium flat-rate box is 20 pounds,including the box which weighs 6 ounces.write and solve an inequality to describe the possible weight ,w, of the contents that liz will ship to her friend if she must use a medium flat-rate box.

Julie was able to walk 16 km through the zoo in 6 hours. how long will it take her to walk 24 km through the zoo?