Magnesium has an average atomic mass of 24.3068 amu and has three isotopes: 24Mg(23.985045 amu), 25 Mg (24.985839 amu) and 26 Mg(25.982595 amu) The 26 Mg isotope has an abundance of 11.1%. what are the abundances of the other two isotopes. Please show work

Answer 1

isotope 26 = 0.111
isotope 25 = x
isotope 24 = 1-x-0.111

(mass*fraction) + (mass*fraction) + (mass*fraction) = 24.3068
Solve for x.