Aradio dealer makes a radio with the price 20% above the cost price and allows 10% discount on it. find his gain percent

Good morning,

Step-by-step explanation:

Let x be the cost price and

     y the final sell price

     p gain percent

the gain precent p = (20/100)-(10/100)-[(20×10)/(100×100)]

                               = (20-10)/100 - 2/100

                               = 10/100 - 2/100

                               = 8/100

example : x=20

x(1+20/100)(1-10/100) = 20(1+20/100)(1-10/100) = 20(120/100×90/100)

                                                                           = 20(10 800÷10 000)

                                                                           = 21.6

20+20p% =21.6 then 20p%=1.6 then p%=1.6/20=16/200=8/100 then p=8.

for more details look at the photo below.

:)

1760 kilometers

step-by-step explanation:

multiply the amount of time the plane took to travel by it's speed

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: