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What is the x and y intercepts of 3x - 8y - 45 = 0

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greyapple | Student | eNoter

Posted June 17, 2013 at 2:21 PM via web

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What is the x and y intercepts of 3x - 8y - 45 = 0

Tagged with intercepts, line, math

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justaguide | College Teacher | (Level 2) Distinguished Educator

Posted June 17, 2013 at 2:25 PM (Answer #1)

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The x and y intercepts of the line given by the equation 3x - 8y - 45 = 0 have to be determined.

Rewrite the equation of the line in the form `x/a + y/b = 1` where a and b are the x and y intercepts respectively.

3x - 8y - 45 = 0

=> 3x - 8y = 45

=> `(3x)/45 - (8y)/45 = 1`

=> `x/(45/3) - y/(45/8) = 1`

=> `x/15 - y/5.625 = 1`

The x-intercept of the line is 15 and the y-intercept is 5.625

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zach2794 | Student , Undergraduate | eNoter

Posted June 18, 2013 at 6:13 AM (Answer #2)

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3x-8y-45=0

The x- and y-intercepts can be found simply by plugging in "0" for the x and y values:

So, since the "y" value of the x-int. will be 0 (x,0), you can plug in 0 for y:

3x-8(0)-45=0, so now just solve for x which gives you 15 for the x-intercept or (15,0)

Now, for the y-intercept, you can do the opposite and plug in 0 for the "x":

3(0)-8y-45=0

And solving for y will give you -5.625 or -8/45 which is also (0,-5.625) for the y-int.

Therefore, the x-int is (15,0) and the y-int is (0,5.625) as shown in the graph:

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