Can someone help me solve this

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

The lines shown below are parallel. if the green line has a slope of -1, what is the slope of the red line?

Aswimming pool is a rectangle with semicircles on the end. the rectangle is 12 meters wide and 30 meters long. the diameter and width of the swimming pool are equal. sketch and label an overhead diagram of the swimming pool. find the area of the swimming pool floor.