The cooking time for a mini-loaf of bread is 5 minutes longer than half the time it takes to bake a regular-sized loaf of bread. If it takes 25 minutes to bake a mini-loaf, how long does it take to bake a regular-sized loaf?

It takes 40 minutes to bake a regular-sized loaf.

Step-by-step explanation:

Let be "r" the time in minutes it takes to bake a regular-sized loaf of bread and "m"  the time in minutes it takes to bake a mini-loaf of bread.

You need to set up the following System of equations using the information provided in the exercise:

In order to solve this exercise, you can apply the Substitution Method.

You already know the value of the variable "m". Then, you can substitute that value into the first equation:

And finally, you must solve for the variable "r" in order to calculate its value.

You get that "r" is:

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:

square root

step-by-step explanation: