What is the simplified form of :
\[\frac{ x^2 - 49 }{ x^2 - 14x + 49 }\]
Show steps please and/or explain how to do this, I am reviewing some material and I forgot how to do this.
factor the top and bottom cancel any like terms
the top is a "difference of squares" it factors this way a^2 - b^2 = (a-b)(a+b)
Ok so it would be: \[\frac{ (x - 7) (x + 7) }{ x^2 - 14x + 49 }\]
for the bottom first list the pairs of factors of 49: 1,49 7,7 are all of them the + on +49 means the factors are the same sign the -14 from -14x means : the - means the largest factor is -. (so here both factors will be -) now look at the pairs. which pair, with both numbers being minus, add up to -14 those will be the factors
Well it would be -7 and -7 because if you add both those you get -14 but if you multiply two negatives you get a positive.
So now I would have: \[\frac{ (x + 7) (x-7) }{ (x-7) (x-7) }\]
Right?
yes, now cancel (x-7) from top and bottom (because anything divided by itself is 1) also, to be complete, make a note: x≠7 (x is not allowed to by 7)
Oh ok so now I would get: \[\frac{ x + 7 }{ x - 7}\]
So that would be the simplified form since it cannot be simplified further right?
yes, that is the answer
Woohoo :D Thanks a bunch, I had forgotten how to do this
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