please help me out with this problem I found the answer but its wrong?

Question

I got the answer by simplifying and the answer was 1/49 but its wrong.

find lim (x + 7) / (x^ 3 + 343 )
X ------ -7 ( negative seven )

Answer 1

343 = 7^3, so
(x + 7) / (x^ 3 + 343 ) =
1 / (x^2 - 7x + 49)
Lim(x-> -7) = 1/(49 + 49 + 49) = 1/147
(Ithink you had a sign error when you factored.)

Answer 2

First try to simplify it:
x^3+343 = x^2(x+7) - 7x(x+7) + 49(x+7)
=(x^2-7x+49)(x+7)
so (x + 7) / (x^ 3 + 343 ) = 1/(x^2-7x+49)

Then substitute x with -7, and it will give the result:
1/(49+49++49) = 1/147

Answer 3

(x^3+ 343)
= (x+7)(x^2-7x+7^2)
so devideing we get
1/(x^2-7x+7^2) and put x = -7 to get 1/147

Answer 4

L'Hopital's rule rides again; differentiate numerator and denominator to get 1/(3x*2). Evaluated at x = -7, this gives 1/147.

Answer 5

this is lim 0/0 when -7 is substituted
by l'hopitlal's rule,
diff num n den separately,

hence, you get,

lim (1)/(3*x^2)
x-- -7

so subs,
the ans is 1/147

Answer 6

I worked out your problem also and to be honest I got -7 also. So if you come up with something different let me know.