Assuming X as M
First oxideSecond oxideOxygen=27.6%Oxygen=30%Metal=72.4%Metal=70%
Formula of 1stOxide=M3O4
Let atomic mass of metal =x
=3x3x+64×100
So
=3x3x+64×100=72.4
=x=56
Now in second oxide, Metal and oxygen are 70% and 30% therefore,
Their atomic ratio is
M O7056:30161.25:1.8751:1.52:3
Therefore, formula of the compound =M2O3