Question

Could somebody please help me study for a pre-algebra test? I have some questions.

Answer 1

We will be here to answer your questions :)

Answer 2

Okay thanks! I really appreciate it.

Answer 3

Okay. sooo, this is really broad, but I don't understand negative exponents.... At all.

Answer 4

So you got some specific questions or do you want me or us to explain you negative exponents from scratch?

Answer 5

Ummmmmmm. Why does a negative exponent make a fraction? I don't understand the basic concept.

Answer 6

Negative exponents simply means this:

\[a^{-x} = {1 \over a^x}\]

Answer 7

yea slaaibak got it

Answer 8

Yes but why are they defined that way?

Answer 9

it is simple

Answer 10

do you know

\[a^x \times a^y= a^{x+y}\]

Answer 11

No.

Answer 12

now say we want
\[a^x \times a^y = 1\]

Answer 13

Well yeah I do sorry.

Answer 14

Okay.

Answer 15

You'd made one negative!!! AHHH I GET IT!

Answer 16

so when we solve that we get

\[a^{x+y}= 1 = a^0\]

Answer 17

thats good! You get it :D

Answer 18

Teehee! Wow that just clicked. My math teacher didn't explain it that way.......

Answer 19

its my pleasure helping you click it :D

Answer 20

So another thing, how do you deal with #s with exponents in a fraction?

Answer 21

Give an example please?

Answer 22

Ummmm. How do you make fractions with this equation thing?

Answer 23

type over

Answer 24

...

Answer 25

3 over 4

\[3 \over 4\]

Answer 26

Use this code: {1 over 2}

would be

\[{1 \over 2}\]

Answer 27

... Um can I just say it?

Answer 28

yea what is your doubt? i do not comprehend it

Answer 29

yeah sure

Answer 30

Okay so if you had y^-5 times 2^3 over y^4 times x^2.

Answer 31

Or something to that effect.

Answer 32

\[ y^-5 \times 2^3 \over y^4 \times x^2.\]

Answer 33

\[{ y^{-5} * 2^3 \over y^4 * x^2}\]

Answer 34

is that your query?

Answer 35

Lol yeah.

Answer 36

You're faster than me xD

Answer 37

i am not lol

Answer 38

=.=

Answer 39

?

Answer 40

If there's multiplication, you can take y^-5 and but it below the line,

\[y^{-5} = {1 \over y^5}\]

You can immediately write 2^3 as 8.

So now you have:

\[{1 \over y^5} * {8 \over x^2 * y^4}\]

Answer 41

put*, not but

Answer 42

Then, you can multiply similar variables with eachother and add the powers.

it becomes:

\[8 \over y^9 * x^2\]

Answer 43

What are you talking about?

Answer 44

about the question you asked

Answer 45

I made a spelling mistake in my post.

Answer 46

Yeah but how did you get y^9?

Answer 47

I know you have to add... Or subtract the exponents or something.

Answer 48

\[y^4 * y^5 = y^{5 + 4}\]

Answer 49

OH okay.

Answer 50

the main aim of such questions is to convert your negative exponents into positive by taking its reciprocal

Answer 51

Um one more thing. How would you get {1 over 9} % of 90. Or something like that.

Answer 52

Aw shoot. I messed up the thing.

Answer 53

\[{1 \over 9}\]

Answer 54

percent is always divided by 100

Answer 55

Yes.

Answer 56

so 1/9 percent is \[(1/9 ) \over 100 = 1\over900\]

Answer 57

1/900

Answer 58

Sure...

Answer 59

of 90 is 1/900 of 90.. of implies multiplication

Answer 60

so it is

1/900 times 90 = 90/900 = 1/10

Answer 61

Yes yes I get it.

Answer 62

That makes sense! Okay that's all! And I have to go. Thank you so much. ^.^

Answer 63

it is my pleasure