Homework help--> Standard Form [algebra 1]?

I have this equation for standard form: Ax+By=C, and i've used it before, but I just don't understand how it applies to this problem.





Larry runs at an average rate of 8 mi/h. He walks at an average rate of 3 mi/h.





a. Define a variable for time spent walking. Define a different variable for time spent running.


b. Write an equation in standard form to relate the times he could spend running and walking if he travels a distance of 15 mi.





Help please?!

Homework help--%26gt; Standard Form [algebra 1]?
First off, you need to define the variables. This is arbitrary. In the standard form equation, your variables are x and y. These variables will represent the time he spends running and walking. So, let x=time running and y= time walking. The rate for each of these is given: 8mi/hr for running, 3mi / hr for walking.


Since your final answer is in miles, x and y have to be expressed in hrs in order to make your units agree.


the general equation in standard form is 8x+3y=C, but part b tells you the total distance traveled is 15 miles, so


8x+3y=15.
Reply:variables:


let x = time spent walking


let y = time spent running





equation:


Ax + By = C





3 miles/hour (x) + 8 miles/hour (y) = 15 miles


3x + 8y = 15
Reply:let t= time


Let x= time spent running


let A= how fast he runs


let B= his walking rate


let y= time spent walking


and C= miles


so (t-x)= y because it is the total time minus the time spent running


so the equation would be...Ax+B(t-x)=15


or 8x + 3(t-x)=15


or simply 8x+ 3y=15