Add or subtract as indicated. Simplify the results if possible. 2x^2/x-5 - 25+x^2/x-5 =
Is this simplifying an expression or solving this for x?
They each ask for two very different things.
simplifying expression
Ok, that means that when you simplify this, you will still have a fraction, but the goal here is to make both denominators the same.
It appears that they are both x - 5.
That is really good. Now we can just simplify the numerators. That would look like this, put all over the common denominator.
\[\frac{ 2x ^{2}-(25+x ^{2} )}{ x-5 }\]
yup
now we factor 25 + x^2
The only tricky part here is that you have to change the +x^2 into a - x^2 because of the negative sign in between the two original fractions. That would look like this, simplified:
\[\frac{ x ^{2}-25 }{ x-5 }\]
This is what you have to factor now. My answer is kind of different from yours; you have 25 + x^2, when it is actually x^2 - 25, which is the difference of two perfect squares.
correct
and tahat can be simplified to (x-5) and (x+5)
that*
Well, DawnR, I was hoping he/she could come up with it himself/herself, but oh well....thanks for giving the answer.
it's not the answer he/she still has one more step to finish it :p
But factoring is a huge part of coming to that correct answer. Right?
but it doesn't count as an answer :)
What do you get, moiz41510?
\[2x ^{2} - (x+5)(x-5) / (x-5)\]
No; the 25 + x^2 does not factor like that at all. Only the difference of two squares factors like that.
see i didn't tell her/him the answer :D
ahh
sorry
Before simplifying you get \[\frac{ 2x ^{2}-25-x ^{2} }{ x-5 }\]
You subtract like this:\[\frac{ 2x ^{2}-x ^{2}-25 }{ x-5 }\]to get this\[\frac{ x ^{2} -25}{ x-5 }\]See? Don't be sorry!
Now the numerator is the difference of two perfect squares. Can you factor that now?
what happened to the 2x^2?
You subtracted 2x^2 - x^2 to get x^2. Look above to my equations.
The x^2 terms combine because they are like terms.
ok got it
Just like 2x - x = x, it's the same thing with the x^2 terms. The x^2 terms combine: subtract 1x^2 from 2x^2 and get 1x^2 left over.
Now can you factor the numerator?
X+5!!
YES!!!!!!!!!!!!!!!!!!!!!!!!!
thankyou so much!
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