(1)
$M^0 \to M^{+3} + 3e$
$N^{+5} + 3e \to N^{+2}$
$M + 4HNO_3 \to M(NO_3)_3 + NO + H_2O$
(2)
\(xC^{-\dfrac{2y}{x}}\rightarrow xC^{+4}+\left(4x+2y\right)e\\ S^{+6}+2e\rightarrow S^{+4}\)
$2C_xH_y + (4x+2y)H_2SO_4 \to (4x+2y)SO_2 +2xCO_2 +(4x+4y) H_2O$