Question

simplify x^2-9 over (x+3)(x+1)

Answer 1

Please help:)

Answer 2

Hint: Cancel factors of 1
\[\frac{(x + 3)(x - 3)}{(x + 3)(x + 1)}\]

Answer 3

I have no idea what to do next:(

Answer 4

if it's the exact same thing over the exact same thing it equals one. If it's one there's no need to write it.

Answer 5

so the answer is one right?

Answer 6

You can only cancel the parts that are the same not the whole thing.

Answer 7

\[\frac{\cancel{(x + 3)}(x - 3)}{\cancel{(x + 3)}(x + 1)}\]

Answer 8

I'm sorry I still don't get it.... is it (x-3) over (x+1)

Answer 9

yes

Answer 10

Lol I'm right

Answer 11

yup

Answer 12

You need to get it. It takes time to type these up :P

Answer 13

I know but i don't know how the steps work.

Answer 14

There's a lot for you to learn.

Answer 15

@Hero can you help with my question

Answer 16

what is your question?

Answer 17

The management of the UNICO department store has decided to enclose a 800 ft^2 area outside the building for displaying potted plants and flowers. One side will be formed by the external wall of the store, two sides will be constructed of pine boards, and the fourth side will be made of galvanized steel fencing. If the pine board fencing costs $6/running foot and the steel fencing costs $3/running foot, determine the dimensions of the enclosure that can be erected at minimum cost.

Answer 18

so the equation would be 12x+6y right? I can only have one variable. but after that I'd find the derivative & critical values right? then what?

Answer 19

800 = xy
P = 12x + 3y

Answer 20

Remember, we don't count the building wall

Answer 21

so P(800) = (12x+3y)+xy?

Answer 22

No bro

Answer 23

x = 800/y

Answer 24

what do i do since idk the lengths?

Answer 25

My teacher won't let us have two variables so the y is confusing me

Answer 26

Yes, exactly, so you substitute x = 800/y into the second equation bro

Answer 27

or you can substitute y = 800/x

Answer 28

P = 12x + 3(800/x)
P = 12x + 2400/x

Answer 29

Now find
P'(x)

Answer 30

P'(x)=12-2400/x^2?

Answer 31

Now set P'(x) = 0 and solve for x

Answer 32

2400/x^2 = 12
2400 = 12x^2
12x^2 - 2400 = 0
12(x^2 - 200) = 0
x^2 - 200 = 0
x^2 = 200
x = + or - sqrt(200)

Distance can't be negative so
x = sqrt(200)

Good luck finding the rest

Answer 33

Thanx @Hero I'm sure you think I'm stupid by now but thanx a lot.

Answer 34

No bro, you're not stupid