Graphing an Equation
Date: 4/4/96 at 22:10:44 From: Anonymous Subject: Graphing How do you graph 2x-y = 10? I just don't understand how to do it. Would you please help? Thank you!
Date: 9/1/96 at 18:29:31 From: Doctor Jim Subject: Re: Graphing Since neither x or y has an exponent you can see, they are both called linear, so this equation forms a line. The easiest way to graph this is to pick some points (x,y) that make the equation true, like x=6, y=2, because 2*6-2 = 12-2=10. If x=7 then y=4. In fact there are an infinite number of solutions for this equation. No matter what you pick for x, you can find a y that will make the left side be 10. Another way to graph it would be to solve it for y. Subtract 2x from both sides so -y=-2x+10, then divide both sides by -1, so that y = 2x - 10. In this form the number in front of x is the slope. In this case the line goes up 2 for every 1 it goes to the right, and the y-axis intercept is -10, so it crosses the y-axis at (0,-10). Remember that the slope means the y coordinate increases 2 every time the x coordinate increases 1. So more points on the line could be found by adding 1 to the x and 2 to the y, i.e., (1,-8), (2,-6), (3,-4), etc. -Doctor Jim, The Math Forum Check out our web site! http://mathforum.org/dr.math/
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