# rational expression

• Nov 9th 2008, 08:02 AM
william
rational expression
simplify.

1. (x^2+3)/x^2 + (x-1)/5

I get (x+2)/5, is this correct?
• Nov 9th 2008, 08:05 AM
masters
Quote:

Originally Posted by william
simplify.

1. x^2+3/x^2 + x-1/5

We're gonna need some parentheses to know what is in the numerator and denominator. This is too ambiguous.
• Nov 9th 2008, 08:08 AM
william
Quote:

Originally Posted by masters
We're gonna need some parentheses to know what is in the numerator and denominator. This is too ambiguous.

I have edited the OP, is it more clear?
• Nov 9th 2008, 08:31 AM
masters
Quote:

Originally Posted by william
simplify.

1. (x^2+3)/x^2 + (x-1)/5

I get (x+2)/5, is this correct?

I don't know how you arrived at your conclusion so I don't know where to correct you. If you're simplifying by putting everything over one denominator, then we need an LCD.

That would be $\displaystyle 5x^2$

$\displaystyle \frac{x^2+3}{x^2}+\frac{x-1}{5}=\frac{5x^2\left(\frac{x^2+3}{x^2}\right)+5x^ 2\left(\frac{x-1}{5}\right)}{5x^2}=\frac{5x^2+15+x^3-x^2}{5x^2}=\frac{x^3-4x^2+15}{5x^2}$