Quote:
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Originally Posted by Slavakion
Yeah, so this was written on the chalkboard in math class. I'm using an r to represent the "repeating bar" in an irrational term.
Code:
x = .9r
10x = 9.9r
10x - x = 9.9r - .9r
9x = 9
x = 1
Any thoughts? It makes sense, although I don't know if it's mathematically polite to do what he/she did in line three -- subtracting an x from one side and a constant from the other ven though they are equal. |
I can understand the fact that .9r = 1 but take a look at your statement:
10x = 9.9r
Since you have already given the definition of x to be .9r, lets go ahead and plug it in here for the heck of it. This gives: 10x = 9x
This is the part that I cant understand
