How do I solve this problem?

3240

Step-by-step explanation:

Sum=n/2(2a+(n-1)d)

=80/2(2*1+(80-1)1)

=40(2+79)

=40*81

=3240

6480.

Step-by-step explanation:

This is an arithmetic series with  first term 2, last term 160 and common difference 2.

Sum = n/2 [ a1 + L)

= (80/2)(2 + 160)

= 40 * 162

= 6480.

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: