Check whether 7+3x is a factor of 3x^3+7x

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

Element x decays radioactively with a half life of 8 minutes. if there are 450 grams of element x, how long, to the nearest tenth of a minute, would it take the element to decay to 37 grams?

Under normal conditions, 1.5 feet of snow will melt into 2 inches of water. during a winter season high in the mountains, 301 feet of snow fell. how many inches of water will there be when the snow melts?