Question

If p(1/q) = -1, then which of the following is NOT necessarily true?
(a) p+q=0
(b) p-q=2p
(c) pq=-p^2
(d) p^2 + q^2 = 2p^2
(e) p= -1/q

Answer 1

(b) p-q=2p

Answer 2

how'd u get that?

Answer 3

p(1/q) = -1

so p=-q

replace all the p's above with -q and see if you get equality

Answer 4

i do get equality

Answer 5

shouldn't on all of them..one of them is bad

Answer 6

which one?

Answer 7

I can't just give the answer

Answer 8

notice that b) is ok

p-q=2p
-q-q=2(-q)
-2q=-2q

Answer 9

what do you get for e

Answer 10

i chose that one as the answer but wasn't sure

Answer 11

p= -1/q

-q=-1/q

this is not always true...if q=2 then

-2=-1/2

Answer 12

so the answer is (e)

Answer 13

thank you :)