Simple equation, but I dont know how to solve for x

  • Context: Undergrad 
  • Thread starter Thread starter vaxop
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Discussion Overview

The discussion revolves around solving various equations for unknown variables, specifically focusing on algebraic and exponential equations. Participants explore different methods and express uncertainty regarding the techniques required to solve these problems.

Discussion Character

  • Homework-related
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant presents multiple equations, expressing frustration over a perceived lack of basic techniques to solve them.
  • Another participant questions the correctness of the first equation provided.
  • A different participant identifies a solution for one of the equations and suggests a method for finding additional solutions.
  • Concerns are raised about the difficulty level of the first equation compared to others presented.
  • Participants discuss the approach to equations where the unknown is in the exponent, suggesting the use of logarithmic rules and substitutions.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the solvability of the equations presented, with some expressing doubt about the correctness of the equations and others proposing methods without agreement on their effectiveness.

Contextual Notes

Some equations may have missing assumptions or require specific techniques that are not universally acknowledged among participants. The difficulty level of the equations varies significantly, impacting the discussion.

Who May Find This Useful

Readers interested in algebraic and exponential equations, particularly those seeking to understand different approaches to solving for unknowns in mathematical expressions.

vaxop
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without using a calculator's graphing or equation solver tools :-p

2000x^16 + 5000x^39 = 3000 + 1600x^12
how can i solve for x?

200(1+i)^7 + 100(1+i)^5 = 300(1+i)^3
i?

1.06^t = 2(1.04)^t
t?

1.08^-n + 1.08^-2n = 1
n?

6x^2-2x-3=0
argh why can't i do these.. i feel like I am missing a basic technique that can be applied to all of these
 
Last edited:
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is it possible?
 
Last edited:
bumpbumpbump
 
As for the second, i=-1 is a solution.
To find the other solutions, divide throughout with (1+i)^3, and introduce z=(1+i)^2.
 
Are you sure you typed your first equation correctly?
 
I was also wondering about that one.
It is order of magnitudes more difficult to solve than the others.
 
Last edited:
how about if the unkown is in the exponent
like..
1.06^t = 2(1.04)^t
t?

1.08^-n + 1.08^-2n = 1
n?
 
Use well-known logarithm rules for the first one, set [itex]x=1.08^{-n}[/itex] in the second one.
 

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