how to find the missing denominator/numerator in multiplying rational expressions

Question

agent47 · Answer

can u post an example?

anonymous · Answer

cn u give an example of what you are asking?

anonymous · Answer

_______/x+2 . x+2/x-3 = x+3

anonymous · Answer

so how can i find the numerator??

shane_b · Answer

Problems like this?$$(\frac{?}{x+2})(\frac{x+2}{x-3})=x+3$$

anonymous · Answer

take the unknown as a variable, say suppose y. then simplify yourexpression and get the value of y by solving

anonymous · Answer

@shane_b yes

shane_b · Answer

The math behind these is essentially same as any other fractions.  In your example, you can immediately cancel out the (x+2)'s on the left side to simplify it.

anonymous · Answer

in your example, y= (x+3)(x-3)

anonymous · Answer

so your numerator would be x^2-9

anonymous · Answer

what does ^ mean?

shane_b · Answer

exponent: $$x^2$$

shane_b · Answer

Here's it done in pretty text:$$\frac{y}{x-3}=x+3$$$$y=(x+3)(x-3)$$$$y=x^2-9$$

shane_b · Answer

Just remember, the normal fraction/equation rules apply...no matter how complicated the problem starts off looking.

anonymous · Answer

thank you so much

shane_b · Answer

you're welcome.  Good luck :)