# Thread: Solving the equation of a line

1. ## Solving the equation of a line

Hi folks,

I am having trouble trying to work out how I go about rearranging the equation I get from my graph in order to work out the value of x (at least i think that is what i need to do!) So my equation is y=3.3468x + 0.6827. I need to find out how to put 0.7545 into the equation but i dont know what i am meant to do!

2. Originally Posted by HowardMoon2010
Hi folks,

I am having trouble trying to work out how I go about rearranging the equation I get from my graph in order to work out the value of x (at least i think that is what i need to do!) So my equation is y=3.3468x + 0.6827. I need to find out how to put 0.7545 into the equation but i dont know what i am meant to do!

I'm not exactly sure of what you mean, but I think you need to find the value of y when x is 0.7547.

The point of this is to substitute (plug in) 0.7547 for x:

$y=3.3468x + 0.6827$

When you
put 0.7545 into the equation
you get:

$y=3.3468(0.7545) + 0.6827$

I think that concept is what you didn't understand. Do you see what it means to "put a number into an equation?" You have to substitute that number for the variable (e.g. x).

3. Thanks for getting back to me.

I thought that was what i was meant to do but it seemed too easy.

So - y=3.3468*0.7545+0.6827=3.2078606. yeh?

4. Originally Posted by HowardMoon2010
Thanks for getting back to me.

I thought that was what i was meant to do but it seemed too easy.

So - y=3.3468*0.7545+0.6827=3.2078606. yeh?
Glad to be of help, and yes that seems to be the right answer.