Question

limits

Answer 1

you have multiply by the conjugate.

Answer 2

to*

Answer 3

okay sooooo

the limit as x approaches 25 when f(x)=(25-x)/(sqrt(x)-5)

understand that you can try looking at (25-x) as (a^2-b^2)

since (a^2-b^2) can be factored into (a-b)(a+b), you can make (25-x) into
(5-sqrt(x))(5+sqrt(x))

Answer 4

Now we have
(5-sqrt(x))(5+sqrt(x))
-----------------
sqrt(x)-5

Answer 5

Then you can factor out a -1 from the denominator to get:

(-1) (sqrt(x)-5)

Answer 6

(-1) (5-sqrt(x))

excuse me

Answer 7

With that as a denominator, you'll see that our equation is now

(5-sqrt(x))(5+sqrt(x))
-----------------
(-1)(5-sqrt(x))

Answer 8

Since both the numerator and denominator have (5-sqrt(x)), that can be cancelled out

Answer 9

Got the rest on your own? :)

Answer 10

is it 1?

Answer 11

Well once you cancel out the (5-sqrt(x)), you're left with

(5+sqrt(x))
--------
-1

Since you are looking for the limit as x approaches 25, you simply plug 25 into x

Answer 12

5+ sqrt(25)
--------
-1

Answer 13

What do you get for that?

Answer 14

-10 (:

Answer 15

There you go! *high five* lol :)

Answer 16

thanks!!!

Answer 17

anytime :)