\(TrongA:n_C=n_{CO_2}=0,15\left(mol\right)\\ n_H=2n_{H_2O}=0,3\left(mol\right)\\ \Rightarrow n_O=\dfrac{4,5-12.0,15-0,3.1}{16}=0,15\left(mol\right)\\ \Rightarrow CTPT:C_xH_yO_z\\ Tacó:x:y:z=0,15:0,3:0,15=1:2:1\\ \Rightarrow CTĐGN:\left(CH_2O\right)_n\\ Tacó:\left(12+2+16\right).n=60\\ \Rightarrow n=2\\ Vậy:CTHHcủaA:C_2H_4O_2\)