Question 486093: can someone please tell me how to graph 4x + y =0
Answer by bucky(2189)   (Show Source):
You can put this solution on YOUR website! Sometimes the answer is a little easier to find if you put the equation into the slope intercept form. The slope intercept form is:
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In this slope intercept form the value of m, that is the multiplier of x, is the slope of the graph line. And the value of +b is the value on the y-axis where the graph crosses.
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The equation you were given is:
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Let's move the 4x to the other side of this equation by subtracting 4x from both sides of the equation as follows:
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On the left side the 4x and the -4x cancel each other out and we are left with the equation:
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Notice that if you compare this with the slope intercept form, it is in exactly the same format. For this equation m, the multiplier of the x, is -4. The minus sign tells you that the slope is negative, meaning that as you move to the right on the graph, the line goes downward. The downward slope is 4. That means that every unit you move to the right along the x-axis the corresponding change in the value of y is 4 units. Since the slope is downward for this problem, that means that every unit you move to the right along the x-axis the value of y goes down 4 units.
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One point on the graph is +b or the constant term in the slope intercept form. It is the point on the y-axis where the graph crosses. In your problem, the value of +b is +0. That means that the graph crosses the y-axis at y = 0 and this is the origin.
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So you can start with a point at the origin, and then as you move 1 unit to the right along the x-axis the graph drops 4 units in the value of y. So when x = -1, the value of y drops to -4. Then as you move another unit to the right along the x-axis (you are now at x = 2), the value of y drops another 4 units from y = -4 down to y = -8. This is the point x = 2 and y = -8.
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You now have the following three ordered pairs on the graph: (0, 0), (1, -4), and (2, -8). Plot these three points and draw an extended line through them to get the graph. When you do that it should look like this:
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Hope this helps you to understand graphing of linear functions a little better.
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