Question 80954
For this problem you can use the slope-intercept equation.  This equation has the form:
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{{{y = mx + b}}}
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In this equation m represents the slope and b is the value on the y-axis where the graph 
intersects the y-axis.
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In this problem you are told that the slope is -2. And you are told that the graph goes through
the origin. This means that the graph intersects the y-axis at a y value of 0. This translates
to m = -2 and b = 0.  Substituting these values into the slope-intercept equation results in 
the equation becoming"
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{{{y = -2x + 0}}}
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You can then simplify it by dropping the 0 to get the equation:
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{{{y = -2x}}}
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The fact that the slope is negative tells you that the graph goes down as you move to 
the right.
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You can now get some points on the graph by assigning values to x and computing the corresponding
values of y.  For example, let x = -5. Plug that value in for x and the equation becomes:
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{{{y = -2*-5 = 10}}}
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So when x is -5, then y = +10. This means the point (-5, +10) is on the graph.
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The problem tells you that (0, 0) is on the graph.
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Then suppose that we let x = +5.  Substituting this value into the equation results in:
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{{{y = -2*5 = -10}}}
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This means that when x equals +5, the corresponding value of y is -10.  So the point
(+5, -10) is on the graph.  If you plot these three points you should see that they 
lie on a straight line.  Take a straight edge and line it on these points. Then extend a 
line through all three points.  When you do you should have a graph that looks like:
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{{{graph(300,300,-15,15,-15,15,-2*x)}}}
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Hope this helps you to understand the problem and see how to get an answer.
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Cheers
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