Question

A metal × with relative atomic mass 56 forms an oxide with formula ×2°3 how many greams of the metal will combine with l0g of oxygen [0=10]

Answer 1

Confusing post but I assume that is X2O3.

molar mass X2O3 = 2*56 + 3*16 = 160
Percent O in X2O3 = (48/160)*100 = 30%.
% X = 70%
0.30 of what is 10 g
10 g O/0.30 = 33.33 g X2O3
0.70*33.33 = 23.33 g = X = 23.33 g of the metal will combine with 10 g oxygen to form X2O3.