How must unit cubes be stacked when used to measure volume?

Pls will give brainliest and all p.s u can zoom in if u cant see plss

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

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