help in determining common denom. for ratl. expressions

[dk_102]

-4/3w+9 + 6/4w+12

Question is simplify/state restrictions

- my question is how would you determine the common denominator?

appreciate any help

dom

 

[jonboy]

Do you mean: \(\displaystyle \L -\;\frac{4}{3w+9} \,+\, \frac{6}{4w+12} \;or\; -\,\frac{4}{3}w \,+ \,9 \frac{6}{4}w \,+\, 12 \;or \; -\,\frac{4}{3w} \,+ \,9 \frac{6}{4w} \,+\, 12\)?? Or something else?

 

[skeeter]

I assume you mean the expression

\(\displaystyle \L \frac{-4}{3w+9} + \frac{6}{4w+12}\)

factor the denominators to see what they have in common ...

\(\displaystyle \L \frac{-4}{3(w+3)} + \frac{6}{4(w+3)}\)

note that the denominators have the factors (w+3), 4, and 3 ... so, the common denominator will be (w+3)(4)(3) = 12(w+3).

\(\displaystyle \L \frac{(-4)(4)}{(4)(3)(w+3)} + \frac{(6)(3)}{(4)(3)(w+3)}\)

\(\displaystyle \L \frac{-16}{12(w+3)} + \frac{18}{12(w+3)}\)

can you finish up now?

 

[dk_102]

thank you

ya thanks skeeter that helps alot wasn't thinking thanks a bunch...

dom

 

[jonboy]

Re: thank you

ya thanks skeeter that helps alot wasn't thinking thanks a bunch...

dom

can you finish up now?