Question 6310: draw the graph of 2x+5y=8.
I don't know how to find x and y . Could you help?
Answer by Earlsdon(6294)   (Show Source):
You can put this solution on YOUR website! In these kinds of problems, you assign values of your own choosing to x (the independent variable) and then you compute the corresponding value of y (the dependent variable). You can then make what is called an input-output table showing these values. It makes things a little easier if you first solve the equation for y by putting it into the slope-intercept form, y = mx + b.
We'll do this for this equation, 2x + 5y = 8
2x + 5y = 8 Subtract 2x from both sides.
5y = -2x + 8 Divide both sides by 5
y = (-2/5)x + 8/5
Now set up the input-output table. The x-value that you assign corresponds to the input and the resulting y-value is the output.
x, y
--------
0, 8/5
1, 6/5
2, 4/5
-1, 10/5
-2, 12/5
Of course, you need only two points to define a straight line but you can calculate any number of points you wish.
Now, on a piece of graph paper on which you have drawn the x-axis (horizontal) and the y-axis (vertical), you can graph some or all of the points in the table and then join them together with a straight line. It should look like the graph shown below:
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