Question

lim x→13 (x^2−19x+78)/(x−13.)

Answer 1

\[\lim_{x \rightarrow 13} \frac{ x²-19x+78 }{ x-13 }\]

Answer 2

Ok I guess I'm supposed to factorise the numerator?

Answer 3

yes you are on the right track ....so can you factorize it?

Answer 4

uh.. 78/13=6
but (x-13)(x+6)=x²-12x+78

Answer 5

so it could be (x-13)(x+6)+7x?

Answer 6

(x-13) (x-6) is the required factorization

Answer 7

ok so if it would be (x-13)(x-6)+7x, then (x-13) cancels out and we're left with x-6+7x=6+6x, when we plug in x=13, we get 6+78=84 ?

Answer 8

what is 7x doing there?

Answer 9

(x-13) (x-6) /(x-13)= (x-6)
13-6 = 7
so 7 is the answer

Answer 10

all righty now I got it... the seven was a huge mistake that's what it was

Answer 11

cool :)