Marc has 45 cd in his collection and corona has 61 if marc buys 4 new cd each month and corina buys 2 new cd each month after how many months will marc and corina have the same number of cds

Plz help plz give me the answer

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.

What values of x satisfy the inequality x^2-9x< 0? how is your answer shown on the graph?