Sunday, April 15, 2007

Unit 8 - HW #60 Sci. Notation & Review for Test

7 comments:

Anonymous said...

I am working on number 25, and and I got up to -10x to the -6 over y to the -2. I know that you would flip the x-6 down to become 1/x6. However, what do you do about the y-2?

Anonymous said...

when doing number 21, why is the answer 4/b4 instead of 4 1/b4?

Mr. Chamberlain said...

(For clarity, b^4 is b to the 4th power)
For pg 431, q21:
I think you are asking, is 4 "times" 1/b^4 a different answer than 4/b^4?

The answer is they are the same, however 4/b^4 would be considered simplest form.

Does that answer your question?

Mr. Chamberlain said...

pg 431 q25

Two approaches (there are more)

Approach 1)
===========
Apply the -2 exponent first, yielding:

5^-2 x^-6 / y^-2

each factor "flips" yielding:

y^2 / 5^2 x^6 which= y^2 /25x^6

Approach 2
===========
Flip the whole schmegeggy first, yielding:

( y / 5x^3)^2

Then, apply the exponent to numerator and denominator, yielding:

y^2 / 5^2 x^6 then simplify to:

y^2 / 25x^6

Ca-peesh?

Mr. Chamberlain said...

Your mistake with #25 was in how you applied the -2 exponent. You apply it to EACH factor (5 and x^3). You were correct for the x^-6 part, but 5^-2 is NOT= -10... it is equal to 1/5^2, better known as 1/25.

Yup or Nope?

Anonymous said...

okay...so I did number 24 because i know that it wasn't homework but i wanted to get practice.

the problem is--
12(x^2y^4)^0/-6x^-2y^2

heres how i did it:

i took out the (x^2y^4)^0 becasue i wasn't sure but my brother said that anything to the zero power equals 1 (sry i forgot).
so now i have:
12/-6x^-2y^2
then i put the x^-2 "up"
so now i have:
12x^2/-6y^2
then i did some more symplifying and got:

-2x^2/y^2 <-- is that right?!?!?

i hope so! please someone try to get back to me asap...i have the test 2morro!! :(

Mr. Chamberlain said...

That is CORRECT, sir! (uh, madam)