Question 622
<b>>>i'm trying to help my daughter with her math homework and i'm stuck,i have 6 problems to graph input,rule,output,ordered pair, 1. y=-3x,x+y=-3,y-2x=4,2y=x-6,x-3y=-9, and y=1/3 x + 1. If you can help I would appreciate it.<<
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I'll just do one of these.  They're all done the same way.
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2y = x - 6
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1.  Solve this for y by dividing both sides by 2:
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y = x/2 - 3
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this is the "rule"
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2.  Arbitrarily choose any value of x.  (You'll probably want to pick whole
numbers divisible by 2 so that y will come out a whole number, although
fractions are perfectly acceptable, just more difficult to work with).  
This value you chose arbitrarily for x is called an "input".
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3.  Suppose we choose input value x=4.  Substitute this input value for x in
y = x/2 - 3
y = (4)/2 - 3
y = 2 - 3
y = -1
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This value of y = -1, is called the "output" for the input of x=4.  
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4. The "ordered pair" is (x, y) or (input, output), which in this case is
` ` (4,-1)
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5. Repeat steps 2-4 several times.  If you also used input values for x, say,
-2, 2, and 0, you get output values for y of -4, -2, and -3, respectively.  So your ordered pairs are (4,-1), (-2.-4), (2,-2), and (0,-3).       
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6. Now plot all these points on a graph, and if you haven't made any mistakes, it will be possible to draw one line that passes through all of them, like this:
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{{{graph(200,200,-5,5,-5,5,x/2-3)}}}
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Edwin <font face = "wingdings" size = 7 color = "red">J</font>