# 2,4-dinitrophenyl hydrazine test

I found this reaction over here:

which illustrates the carbonyl test but looks fuzzy.

Assuming that the R in the product is a typo for H, I couldn't conserve the number of Nitrogen atoms.

What is the correct reaction?
Is this correct?
Is there a possibility of a methyl substitution on the ring in a variant of this test?

As you have already imagined, there is no magical $\ce{NO2}$ to $\ce{CH3}$ conversion in this classical reaction ;-)