On the track and field team, 3/8 of the members do the hurdles.
of the members who do the hurdles, 4/5 also do the long jump.
if there are 40 members on the track team, how many do both the hurdles and the long jump?

15 members do the hurdles,

12 of them do long jump

Step-by-step explanation:

There are 40 members.

3/8 of all members do the hurdles, so the hurdles do

15 members do hurdles, 4/5 of them do the long jump, so

do the long jump.

12 members of the track team do both the hurdles and the long jump.

Step-by-step explanation:

As there are 40 members on the track team, if 3/8 of them do the hurdles, we have to divide 40 by 8 and the multiply the result by 3 to know the number. So, 40 / 8 is 5, and 5 x 3 is 15. Therefore, 15 members do the hurdles.

Of the members who do the hurdles, 4/5 of them also do the long jump. Using the same method, as 15 / 5 is 3, and 3 x 4 is 12, 12 members of the track team do both the hurdles and the long jump.

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: