A 100.0 g sample of a metal m is burned in air to produce 103.7 g of its oxide with the formula m2o. what is the atomic mass of the metal?

The molar mass should be 14.898g/mol. I used the equation 100gx (1/xg/mol) x (1mol/2mol) x (16g/mol+x) / 1) = 103.7 and solve for x. I found that equation using stoichiometry and the equation 2m+1/2O2-->m2O The molar mass of the metal I set to x and the molar mass of the metal oxide is 16+x.