Question

Which of these equations would not be in quadratic form?
A.X^4-13X^2+36=0
B.2X^(2/5)+X^(1/5)-6=0
C.6x^3+2x^2-8X=0
D.3(2/x-4)^2+5(2/x-4)-2=0

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.

Answer 1

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.

Answer 2

76