SOLUTION: Find the slope, if any, of this equation: {{{21-7x=18+x}}}

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Question 155668: Find the slope, if any, of this equation: 21-7x=18%2Bx
Found 2 solutions by Alan3354, Adam:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
21-7x=18%2Bx
=3+=+8x
x = 3/8
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Since there's no y term, it's a line thru (3/8,0) parallel to the y-axis. That is, x = 3/8 no matter what y is.
It's vertical, so the slope is infinite.

Answer by Adam(64) About Me  (Show Source):
You can put this solution on YOUR website!
First we need to get it into standard form which is Ax+B=0
21-7x = 18+x //-x
21-8x = 18 //-18
3-8x = 0 //reorder
-8x+3 = 0 //*(-1) (looks better ;} )
8x-3 = 0
The equation of the form Ax+B=0 has slope A, what does B value does ? Well, as you see from the equation B adds constant value at every point, thus B moves the line upp or down (if B is negative), A rotates the line (every point is multiplied by that number) and by rotation alone we can increase or decrease slope.
There is also alternative definition, so let's check it.
Slope = f(x2) - f(x1) / x2 - 1
let x1 = 1 and x1 = 3
(x is independent variable so you can choose any value you want)
( f(x1) is left hand of our equation suplied with x1)
{(8*3 - 3) - (8*1 - 3)} / (3 - 1) = 8
you can try it also for other values if you want ;}
Cheers,
Adam