When you add or subtract a negative number to both sides of an inequality, you should always reverse the sign?

Arectangular prism is 3 meters long, 6 meters wide, and has a height of 9 meters. what is its surface area?

Amerchant has coffee worth $60 a pound that she wishes to mix with 50 pounds of coffee worth $90 a pound to get a mixture that she will sell for $70 a pound. how many pounds of the & 60 coffee should be used?

Arecipe calls for 32 fluid ounces of heavy cream.how many 1 pint containers of heavy cream are needed to make the recipe?