Need to know in 30 minutes! i don't know it. i need answers.

Given that (x-3) is a factor of f(x)=x^3+ax^2-x-6, find a and hence the number of real roots or the equation f(x)=0

Iwill give brainliest only if your correct the words subsequent and submerge both contain the prefix sub. based on this information, what does the prefix sub most likely mean? a) under or secondary b) true or verifiable c) tricky or difficult d) around or centered on

To make a monster appear large in a movie, a human actor wore a costume and walked through a scale model of a city. the scale used was 1 inch = 15 feet. the actor is 60 inches tall. how tall does the monster appear in the movie? question 5 options: 720 feet 75 feet 4 feet 900 feet