(3x^3+19x^2+13x+42)/(x+6)
lim--6
please help solve

Question

(3x^3+19x^2+13x+42)/(x+6)
lim->-6
please help solve

myininaya · Answer

try synthetic division to factor the numerator and cancel the x+6's

anonymous · Answer

I think the factoring of the numerator was what was giving me a problem

anonymous · Answer

do you get 0 in the numerator?  if so, you know you can factor as 
$$(x+6)\times \text{something}$$

anonymous · Answer

yea i got that far but i'm having a hard time factoring the numerator

anonymous · Answer

don't think about how to factor it .  just make sure one of the factors is 
$$(x+6)$$ and figure out what the rest has to be

anonymous · Answer

first term has to be 
$$3x^2$$ for sure.  last term must be 7

anonymous · Answer

or just hopital it up

anonymous · Answer

didn't get there yet

anonymous · Answer

much quicker... you get:

9x^2 + 38x +13 over 1

anonymous · Answer

factors as 
$$(x+6)(3x^2+x+7)$$ by pure reason.

anonymous · Answer

so answer is = 109

anonymous · Answer

cancel the x + 6 then replace x by -6 in 
$$3x^2+x+7$$ to get your answer.  l'hopital will work but 
a)  you didn't even get to differentiation yet so you don't know it and 
b) it is like killing a flea with an elephant gun

anonymous · Answer

thank you very much everyone, much clearer now!

anonymous · Answer

ppl on these sites tend to just want answers so im putting it out...if he wants work i woulda done you're way too provided his knowledge.