Which of these equations would not be in quadratic form?
I think its between C or D. C because the exponents are different not doubled and D because its set up is completely the opposite from all the others.
It is in fact C
D is just a quadratic in (2/x-4), because if you substitute u=2/x-4, you have just 3u^2+5u-2=0
It is C because as you say, there is not
a term with twice the exponent of the other.