3 Dave can drive from Abdet to Bentall by two routes. The old route goes in roughly a straight line while the new faster route is 26% longer. Dave's average speed on the new faster route is 40% higher than his average speed on the old route. (a) By what percentage is Dave's journey time reduced by taking the new route compared to the old? [2]

10 % of the total time will be saved on the new route with the new speed.

Step-by-step explanation:

Let x miles  be the old route. Then the new route would be 1.26 x miles

Let y be the speed on the old route . Then the speed on the new route would be 1.4 y .

And let t be the time on the old route

Speed = Distance / Time

or

Time = Distance / Speed

t= x/y

     Time for the new route   = 1.26x/ 1.4y= 0.9 t

0.9 t means 90% of the old time will be required to cover 1.26x  miles with 1.4 y speed.

And 10 % of the total time will be saved on the new route with the new 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:

answer: y = 3/2 x - 3

y = 1/8 x - 3/4 that would be your correct option

step-by-step explanation: w