Which expression is equivalent to 42x^-4y^10z^3 / 6x^2y^-2z​

We just started the introduction into circles and i have no idea how to do this.

Use the method of cylindrical shells to find the volume v generated by rotating the region bounded by the curves about the given axis. y = 7ex, y = 7e^-x, x = 1; about the y-axis

Atown has a population of 17000 and grows at 2.5% every year. to the nearest year, how long will it be until the population will reach 19600?