Posted - 09/26/2013 : 17:21:59 Find the equation that has intercepts (0, -7) and (3, 0).

I don't remember how to do this at all. Please explain how to get the answer instead of just giving the answer.

Thanks in advance to everyone who responds. :-)

4 L A T E S T R E P L I E S (Newest First)

Nichelle1012

Posted - 09/27/2013 : 11:46:18

quote:Originally posted by the_hill1962

Intercepts mean where the graph of the equation crosses the axis. An x intercept has a point such as (x,0) because any point that is on the x axis would have a y coordinate of zero. A y intercept has the form (0,y). If you need more explanation at this point, please ask before reading further. In your problem, the x intercept is (3,0) and the y intercept is (0,-7)

Hopefully you are familiar with the slope intercept form of a linear equation: y = mx + b where b is the y intercept and m is the slope. So, so far you know the equation will have b=-7 since -7 is the y intercept in your problem. Now to figure out m (the slope). Hopefully you know how to calculate the slope. If not, look up the formula or ask us. The slope for your points is (-7-0)/(0-3) and that is the fraction 7/3.

So, you can now write the equation y = (7/3)x - 7

the_hill1962, thanks!! I do know how to calculate the slope. I got as far as y=(7/3)x-7, but got stuck as to what to do from there. Now I know that you cancel out the (7/3)x and add it to y, which gives (-7/3)x+y=-7. Then I multiply everything by 3, which then gives me the final solution of -7x+3y=-21. Once again, thanks. :-)

the_hill1962

Posted - 09/27/2013 : 08:51:14 Intercepts mean where the graph of the equation crosses the axis. An x intercept has a point such as (x,0) because any point that is on the x axis would have a y coordinate of zero. A y intercept has the form (0,y). If you need more explanation at this point, please ask before reading further. In your problem, the x intercept is (3,0) and the y intercept is (0,-7)

Hopefully you are familiar with the slope intercept form of a linear equation: y = mx + b where b is the y intercept and m is the slope. So, so far you know the equation will have b=-7 since -7 is the y intercept in your problem. Now to figure out m (the slope). Hopefully you know how to calculate the slope. If not, look up the formula or ask us. The slope for your points is (-7-0)/(0-3) and that is the fraction 7/3.

So, you can now write the equation y = (7/3)x - 7

Nichelle1012

Posted - 09/26/2013 : 21:52:02

quote:Originally posted by Ultraglide

I am sure your text shows you how to find the equation of a line given two points. If you don't have a text, just search the net.

Ultraglide, if I had a textbook to show me, I wouldn't have posted the question for help. I'm not in a class; I am just doing sample problems to em refresh my memory. Also, I have searched the web for help. The website that I am seeking help on is www.mathgoodies.com. As for any other sites, I obviously couldn't find what I'm looking for. Thank you so much. Your reply was SO helpful.

Ultraglide

Posted - 09/26/2013 : 19:01:10 I am sure your text shows you how to find the equation of a line given two points. If you don't have a text, just search the net.