Question 78569
Given the following information for an equation and its graph:
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Slope: - 3/4; y-intercept: (0, 8)
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The slope-intercept equation says that the equation is of the form:
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y = mx + b
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in which m is the slope and b is the point at which the graph crosses the y axis.
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All you have to do now is to substitute the given values of the slope and y intercept
into the slope intercept equation.  When you make the two substitutions you get:
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y = (-3/4)x + 8
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You already know one point on the graph.  That point is (0, 8) the point at which the 
graph crosses the y-axis.  You can plot that point by going +8 units up the y-axis
and putting a dot there.
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Now you can pick a convenient value for x, substitute it into the equation and find the
corresponding value of y.  Let's pick x = 4 and substitute it into the equation to get:
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y = (-3/4)(4) + 8
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Multiply out (-3/4) times 4 and you get -3.  This makes the equation become:
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y = -3 + 8
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and adding the terms on the right you find that y = +5 when x = +4.  Therefore, you know
that (4, 5) is another point on the graph.  
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Just as a check, let's find one more point on the graph.  Suppose we let x = 8 and 
substitute that value into the equation.  If we do that we get:
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y = (-3/4)*8 + 8 = -6 + 8 = +2
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Therefore, we know that when x = 8, y = 2 so the point (8, 2) should be on the graph.
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Plot the three points (0, 8), (4, 5) and (8, 2) and draw a straight line that runs 
through all three of these points.  That should be the graph and it should look somewhat 
like this:
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{{{graph (400,400,-20,20,-20,20,(-3/4)x+8)}}}
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Hope this helps you to understand the problem and how to solve it.