Question

help? @johnweldon1993

Answer 1

oh i got dis
b because the restricted line macks the equallatrialitgy mach the tylegori something along those lines.

Answer 2

are you sure

Answer 3

yes

Answer 4

how do you know? can you explain

Answer 5

yes please explain...

Answer 6

@gabriel54321

Answer 7

i thought umm... i did sorta explain.

Answer 8

Okay @sierraleone17 we have

\[\large \frac{u^2 - 9}{(u - 3)^2}\]

Firstly we want to state the restrictions...what value of 'u' will make the denominator = 0?

Answer 9

(u + 3) (u+3)

Answer 10

Well there are a couple different ways of seeing this....we can write it out as

\[\large (u - 3)(u - 3)\]

and we can see that in both cases...u = 3 will make that = 0

so overall \(\large u \cancel{=} 3\) okay?

Answer 11

okay

Answer 12

whats wrong with my answer

Answer 13

Now that that is out of the way (besides the fact that we can see that D will be our answer)

We need to simplify this...

\[\large \frac{u^2 - 9}{(u - 3)^2}\]

Lets again write out the bottom part

\[\large \frac{}{(u - 3)(u - 3)}\]

But how can we factor the top? what does u^2 - 9 factor into?

Answer 14

(u-9) (u-9)

Answer 15

Not quite..that would be true if the top was

\[\large (u - 9)^2\] because then yes we would just write it twice...

however this is \[\large u^2 - 9\]

And this will factor into (u - 3)(u + 3)

Why? well lets see if it wourks out going backwards...

u times u is u^2
u times 3 is 3u
-3 times u is -3u
and 3 times 3 = -9

so we have

u^2 + 3u - 3u - 9

which simplifies down to

u^2 - 9 like we had...

so our factor is

\[\large (u + 3)(u - 3)\] alright?

Answer 16

ohhh okay that makes sence

Answer 17

sense*

Answer 18

oh wait your 21 wonder u know all this

Answer 19

haha nooo duh ^

Answer 20

I JUST THOUGHT ABOUT IT

Answer 21

So now we have

\[\large \frac{(u - 3)(u + 3)}{(u - 3)(u - 3)}\]

see anything that can cancel out? I do :P

\[\large \frac{\cancel{(u - 3)}(u + 3)}{\cancel{(u - 3)}(u - 3)}\]

so we end up with
\[\large \frac{u + 3}{u - 3}\] so it looks like once and for all our answer is indeed D

Answer 22

thank you!!!