A group of 12 students has a mean height of 58 inches. Another group of 6 students has a mean height of 52 inches. What is the mean height of the 18 students? Explain how you found your answer.

56 inches  

Step-by-step explanation:

A weighted average must be made, that each average has an assigned weight and in this way a resulting average can be obtained.

That is, the average of 12 students has a weight of 12 and the average of 6 students has a weight of 6, and then divide by the total weight, that is, 18, like this:

(58*12 + 52*6) / 18 = 56

56 inches tall is the average of the 18 students

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option