Suppose that you are a teacher with a total of 100 students 10 among them come from a disadvantaged and their average in year 1 is 80/100. All of the other students are not considered disadvantaged and have an average of 90/100. What is the overall average for your students in year 1?

  89/100

Step-by-step explanation:

The average weighted by the number of students is ...

  (90(0.90) +10(0.80))/100 = (81 +8)/100 = 89/100

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation: