Question

(q^(-2)-r^(-2))/q^(-1)-r^(-1))

Answer 1

I know the answer is q+r/qr but I have now idea how they got the answer

Answer 2

here we have to use two laws of exponents

first is \[a ^{m}/a ^{n} = a ^{m-n}\]
and
\[a ^{-m} = 1/a ^{m}\]

Answer 3

\[\frac{q^{-2}-r ^{-2}}{q ^{-1}-r ^{-1}}\]right?

Answer 4

correct

Answer 5

thats right @ cali

Answer 6

\[q^{-2-(-1)} +r ^{-2-(-1)}\]

Answer 7

\[q ^{-2+1}+r^{-2+1}\]

Answer 8

\[q^{-1}+r^{-1}\]

Answer 9

\[\frac{1}{q+r}\]

Answer 10

so
1 1 r^2 - q^2
q^(-2) - r^(-2) = ------ - ------- = ----------------
q^2 r^2 q^2 * r^2

1 1 r - q
and q^(-1) - r^(-1) = ------- - ------ = -----------
q r qr

Answer 11

how did the denominator become a multiplication problem?

Answer 12

Now putting these together we get


q^(-2) - r^(-2) r^2 - q^2 q * r (r-q) (r+q) ( q*r)
---------------- = -------------- x ---------- = ----------------
q^(-1) - r^(-1) q^2 * r^2 r - q (q*r)(q*r) (r-q)

cancelling out common factors we get


q^(-2) - r^(-2) (r+q) r + q
---------------- = ----- = -----------
q^(-1) - r^(-1) (q*r) qr

Answer 13

what do you mean chris by saying "denominator became a multiplication problem"??

Answer 14

it was a subtraction problem, I'm sorry, you are righ on the money I'd give you 2 gold stars if I could and become a fan...I just don't understand

Answer 15

ok i'll break it down further...

Answer 16

i understand the cancelling at the end but how you change the q^-1-r^-1 into q^1 * r^1 i don't understand

Answer 17

see numerator of the given problem is q^(-2) - r^(-2)

q^(-2) = 1/q^2 and r^(-2) = 1/r^2 as per the law i gave


so it becomes
1 1
q^(-2) - r^(-2) = ------ - -------
q^2 r^2

now this is of the ty[pe fraction - fraction and so we have to take LCD

here since we do not have numbers, we take LCD as product of the terms in the denominator to get q^2*r^2

so then we get

r^2 - q^2
q^(-2) - r^(-2) = ----------
q^2 * r^2

We do similarly for

q^(-1) - r^(-1)


do you understand now??????

Answer 18

hold on let me read... lol your being a big help thanks

Answer 19

ok, however if u hv a SKYPE account, v cud hv voice chat n it will b easier to explain

Answer 20

yea, i'll check into it, but I don't have it yet but if I see you on again I'll definitely hit you up

Answer 21

oooohhh that's the common denominator

Answer 22

that's where I've been fkn up

Answer 23

YEAH !!!!!!!

Answer 24

yea, I totally understand now dude, wow thanks

Answer 25

GOOD

now give me the second medal..... :))

Answer 26

wish I could

Answer 27

here i got one for ya

Answer 28

check the board
lol

Answer 29

where ??????