System of 2 Equations: Homework Statement and Attempt Solution

akaliuseheal
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Homework Statement


[/B]
It's a system of 2 equations.

upload_2017-1-16_14-4-4.png

upload_2017-1-16_14-4-10.png


Homework Equations

The Attempt at a Solution


My attempt is not worth writing here.
Results I got using Microsoft Mathematics without showing me step by step.
upload_2017-1-16_14-5-49.png
 
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akaliuseheal said:

Homework Statement


[/B]
It's a system of 2 equations.

View attachment 111650
View attachment 111651

Homework Equations

The Attempt at a Solution


My attempt is not worth writing here.
Results I got using Microsoft Mathematics without showing me step by step.
View attachment 111652

Your attempt is worth it! It shows us you made effort to solve the question.

You have that ##y## must be equal to both ##\frac{1}{750} + \frac{8}{x}## and ##\frac{3}{2500} + \frac{12}{x}##

Thus you need to solve for ##x##: ##\frac{1}{750} + \frac{8}{x} = \frac{3}{2500} + \frac{12}{x}## and then substitute your answer for ##x## to obtain the value for ##y##
 
The most straight-forward way to solve a system of equations (although not always the most efficient way) is:
  • Use the first equation to solve for one variable in terms of the rest
  • In the second equation, replace that variable by its value (found in step 1). This will give you an equation involving one fewer variable.
  • Now, solve for a second variable.
  • Continue for as many equations as you have (which should be the same as the number of variables)
In your case, the first equation already gives you y as a function of x. So just use that value of y in the second equation, and see what you get.
 
Okay, so I did manage to solve it. I was stuck for some time on fractions. Thanks
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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