Solving Linear Equations, such as 4xy+2y=9

L

lauren

New member
Joined
Dec 3, 2006
Messages
5
I do not get how to solve Linear equations at all. I don't even know where to start. Is there anyone who could just maybe explain or walk me through it? I'm new to this site so I'm not sure how this works, but thanks in advance.
 
Re: Solving Linear Equations

lauren said:
I do not get how to solve Linear equations at all. I don't even know where to start. Is there anyone who could just maybe explain or walk me through it? I'm new to this site so I'm not sure how this works, but thanks in advance.
Click to expand...

Please post an example of a specific problem you are having trouble with, and show us what you have done to try to solve it. That will give us an idea of what kind of problems you're working with, and what might help you to better understand the process of solving that kind of problem.
 
Okay, here goes. Please bear with me as I have never had to typ out math problems like this before.

4xy+2y=9

THis is what I did, or tried.

4xy-2y=9
-y -y
________
4x+1y=9
I also got it is not a linear equation.

Does any one know if this is right?
 
lauren said:
4xy+2y=9
Click to expand...
This is not a linear equation, and, until it is specified for which variable you are supposed to solve, there is no way to proceed.

Sorry; your book should have used the correct terminology, and should have provided instructions. Please see if your instructor can provide corrected information.

Eliz.
 
The directions were "Determine wherther each equation is a linear equation. If so, write the equation in standard form." if that helps.
 
"Standard form" has no standard meaning, so we can't help you with that. To determine if the equation is linear, try looking in your book (or your class notes) for the definition of a linear equation. What does it say?

Eliz.
 
"A linear equation is the equation of a line. Linear equations can ofgen be written in the form Ax+By=C. THis is called the standard form of a linear equation."

That's all it says about it in the book. My teacher doesn't give notes. She just kind of expects us to know it.
 
lauren said:
"A linear equation is the equation of a line. Linear equations can ofgen be written in the form Ax+By=C. THis is called the standard form of a linear equation."
Click to expand...
Can your equation, 4xy + 2y = 9, be rearranged to be in the form Ax + By = C? If so, it's linear. If not, it isn't.

Eliz.
 
lauren said:
I do not get how to solve Linear equations at all. I don't even know where to start. Is there anyone who could just maybe explain or walk me through it? I'm new to this site so I'm not sure how this works, but thanks in advance.
Click to expand...

If your post is correct then one way to linearize the equation is to change variable.

4xy + 2y = 9 → 1/y = 4/9 * x + 2/9

The equation above is linear relation between 1/y and x.

you can also write it as:

y = 4.5/(2x + 1)

and equation above is linear relationship between 'y' and '1/(2x+1).

choose your poison......
 
You must log in or register to reply here.
Top