Given that AC=30, AB=5x-21, BC=3y+4, CD=2x-3, and DA=4x+1, find the indicated variables for each question. Find the value of x, y, z.

Henry is an avid reader, he devours 90 pages in half an hour how many pages has henry read per minute?

Jack has a piece of red ribbon that is two times as long as his piece of blue ribbon. he says that he can use two different equation to find out how long his piece of red ribbon is compared to his piece of blue ribbon is. is he correct? explain his reasoning

Arecipe calls for 2 2/4 cups of raisins, but julie only has a 1/4 measuring cup. how many 1/4 cups is needed to measure out 2 2/4 cups of raisins?