Use mental math to find the sum. draw or describe the strategy you use. 52+19

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.

Two numbers have a sum of -19. one number is x. what expression represents the other number?

Y= 4x + 3 y = - 1 4 x - 5 what is the best description for the lines represented by the equations?