Question 72976
A little more standard way of writing the equation is:
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y = 3x + 5
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Your version was correct, but it's a little more conventional to write it this way.
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Now the thing to do is just pick values for x, and use the equation to calculate the corresponding
value for y.  Finally you plot the points and then use a straight edge to draw a line through them.
That will complete the graph.
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Example 1.  Let x = 0.  Usually a good choice because it makes terms drop out or become much simpler. 
In this equation when x = 0 the term 3x goes away and the answer becomes y = 5.
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On the coordinate system this would be the point x = 0 and y = 5.  Notice that this would
be on the y-axis up 5 units. Mark that point. [A standard way for identifying this point
is (0, 5) where the first number is the x value and the second number is the y value.]
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Next example. Pick another value for x.  Maybe x = +2.  Substitute that value for x in the
equation {{{y = 3x + 5}}}.
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When you do you get{{{y = 3*2 +5 = 6 + 5 = 11}}}. So another point on the graph is where 
x = 2 and the corresponding y value is 11 or just simply (2, 11).
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For a third point try letting x equal -5.  Then use the equation to find the corresponding
value of y:
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{{{y = 3*(-5) + 5 = -15 +5 = -10}}}
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This point is (-5, -10)
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You now have three points that should line up so that you can use a straight edge to draw
a line through them all and in both directions.  When you get done your graph should look 
something like this:
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{{{graph(400,400,-20,20,-20,+20,3x+5)}}}
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Hope this helps you to understand the problem now.