Just how do you do this i don’t get what x is and just how to solve (there is pic attached)

Will mark brainliest question in the pic.

The diameter of a ball is 8 in. what is the volume of the ball? use 3.14 for pi. enter your answer as a decimal in the box. round only your final answer to the nearest hundredth.

The swimming pool is open when the high temperature is higher than 20∘c. lainey tried to swim on monday and thursday (which was 3 days later). the pool was open on monday, but it was closed on thursday. the high temperature was 30∘c on monday, but decreased at a constant rate in the next 3 days. write an inequality to determine the rate of temperature decrease in degrees celsius per day, d, from monday to thursday.