Solve this system of equations

{y = 2x
{x = -y + 6

In the coordinate plan (-6,9) b (3,9) c (3,3) def is shown in the coordinate plan below

The height of a triangle is 4 in. greater than twice its base. the area of the triangle is no more than 168 in.^2. which inequalitycan be used to find the possible lengths, x, of the base of the triangle?

Sara can take no more than 22 pounds of luggage on a trip.her suitcase weighs 112 ounces.how many more pounds can she pack without going over the limit?