Question

Calculus- derivatives.

I have two questions i need help with. My teacher told me i got a part of each answer wrong. Can someone please tell me which part and what the answer is.

First one:
-22x^-5 - 17x^-11/ 21x^-4 = 22x^-2/21 + 17x^-8/3.

Second one:
7x^2+5x^9/4x^7= 5x/2- 35/4x^6

Answer 1

can you post a screenshot of the full problem?

Answer 2

@jim_thompson5910 Yes i can.

Answer 3

Its questions 2 and 3. I got the rest by myself.

Answer 4

Ok let's focus on problem 2 for now

Answer 5

Im sorry! it was 3 and 4!

Answer 6

ok so let's focus on problem 3

Answer 7

I'm assuming problem 3 is supposed to look like this

\[\Large \frac{-22x^{-5}-17x^{-11}}{21x^{-4}}\]

Answer 8

or is it supposed to be this?

\[\Large -22x^{-5}-\frac{17x^{-11}}{21x^{-4}}\]

Answer 9

Its the first one.

Answer 10

before we do any derivatives, let's simplify the expression

Answer 11

We can break up the fraction to go from this
\[\Large \frac{-22x^{-5}-17x^{-11}}{21x^{-4}}\]
to this
\[\Large \frac{-22x^{-5}}{21x^{-4}}-\frac{17x^{-11}}{21x^{-4}}\]
agreed?

Answer 12

Yes.

Answer 13

how would you simplify each fraction? any ideas?

Answer 14

hint:

http://www.onlinemathlearning.com/image-files/xari121.gif.pagespeed.ic.vFV2Lan_oa.png

Answer 15

I feel like it would be the fifth rule?

Answer 16

the second actually

Answer 17

we're dividing power expressions of the same base (x) so we subtract exponents

Answer 18

So -4 minus -4?