Answer
a) $CH_4+2O_2\rightarrow CO_2+2H_2O$
b) $C_3H_8+5O_2\rightarrow 3CO_2+4H_2O$
c) $C_2H_5OH+3O_2\rightarrow 2CO_2+3H_2O$
Work Step by Step
a) $CH_4+2O_2\rightarrow CO_2+2H_2O$
b) $C_3H_8+5O_2\rightarrow 3CO_2+4H_2O$
c) $C_2H_5OH+3O_2\rightarrow 2CO_2+3H_2O$