Gabby and sydney bought some pens and pencils. gabby bought 4 pens and 5 pencils for $6.71. sydney bought 5 pens and 3 pencils for $7.12. find the cost of each.

The cost of each pens is $1.19

The cost of each pencils is $0.39

Step-by-step explanation:

Given as :

The number of pens bought by Gabby = 4

The number of pencils bought by Gabby = 5

The number of pens bought by Sydney = 5

The number of pencils bought by Sydney = 3

The total cost of Gabby items = $6.71

The total cost of Sydney items =$7.12

Let The cost of each pens = x

And The cost of each pencils = y

Now, According to question

For Gabby

4 x + 5 y = $6.71           .............1

For Sydney

5 x + 3 y = $7.12           .............2

Now, Solving both equations

5 × (4 x + 5 y) - 4 × (5 x + 3 y) = 5 × 6.71 - 4 × 7.12

Or, 20 x + 25 y - 20 x - 12 y = 33.55 - 28.48

Or, (20 x - 20 x) + (25 y - 12 y) = 5.07

or, 0 + 13 y = 5.07

∴ y =

I.e y = $0.39

So, The cost of each pencils = y = $0.39

Again , put The value of y in eq 1

I,e 4 x + 5 y = $6.71    

Or, 4 x + 5 × 0.39 = 6.71

or, 4 x + 1.95 = 6.71

or, 4 x = 6.71 - 1.95

or , 4 x = 4.76

∴  x =

I.e x = $1.19

The cost of each pens = x = $1.19

Hence The cost of each pens is $1.19

And The cost of each pencils is $0.39   Answer

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:

step-by-step explanation:

the answer is 128