Jose walks at a rate of 4 miles per hour and runs at a rate of 8 miles per hour. Each week, his exercise program requires him to cover a total distance of 20 miles with some combination of walking and/or running. Write an equation that represents the different amounts of time Jose can walk, x, and run, y, each week

Here we can use the relationship:

Distance = time*speed.

When Jose walks, his speed is 4 mph.

Then if he walks for X hours, the distance that he will travel is:

D = 4mph*X

When Jose runs, his speed is 8mph.

Then if he runs for T hours, the distance that he will travel is:

D´ = 8mph*Y

And we know that he travels in total 20 miles, then we must have that:

D + D´= 20mi

This leads to:

4mph*X + 8mph*Y = 20mi

Where X is the time that he walked, and Y is the time that he runed.

Then the equation that represents the different amounts of times that Jose runs and walks  is:

4mph*X + 8mph*Y = 20mi

Where we can not really find the solutions for Y and X, because there is only one equation and two variables.

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:

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step-by-step explanation: