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Help me graph: sketch the graph of each line 1) x=-1 2)2x-5y=53) x=-14)

User Angus L
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1 Answer

19 votes
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The first equation we are asked to graph is the simple equation:

x = -1

So, we create a table for it that has in the first column the x values, and in the second column the associated y values.

SInce the equation says x = -1 no matter what the value of y is, we can write any y values in the column for y

We end up with pairs of points of the form:

(-1, 0)

(-1, 2)

(-1, 3)

(-1, 5)

(-1, -4)

and so forth, with all os them having a -1 in the first coordinate (the x-coordinate)

Notice that such points give us a vertical line when we join them, it is a vertical line going through the X = -1 point on the x-axis.

where the line x = -1 is plotted in red.

Now, for the second line that reads:

2 x - 5 y = 5

we solve for y in order to make our calculations easier:

add 5 y to both sides:

2 x = 5 + 5y

subtract 5 from both sides:

2 x - 5 = 5 y

now diide both sides by 5:

y = (2 x - 5) / 5

So, let's find at least three points that define our line

Notice that when x = 5 , we get:

y = (10 - 5) / 5 = 5 / 5 = 1

So we draw the point (5, 1) on the x-y plane

When x = 0 we get:

y = (2 (0) - 5) / 5 = - 5/5 = -1

So we draw the point (0, -1) on the plane

And finally, we use the point x = -5 and get:

y = (2 (-5) - 5) / 5 = -15/ 5 = -3

So we draw the point (-5, -3) on the plae.

Then we draw a line connecting the three points we found, as shown below:

Help me graph: sketch the graph of each line 1) x=-1 2)2x-5y=53) x=-14)-example-1
Help me graph: sketch the graph of each line 1) x=-1 2)2x-5y=53) x=-14)-example-2
User Nam Duong
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3.0k points