Copper has 2 known isotopes: ^63CU atomic mass= 62.9298 and ^65 CU atomic mass=64.9278. The average atomic mass of copper is 63.546 amu. Calculate the fraction(percent) of each of the 2 isotopes of copper

Answer 1

63.546=X*62.9298+ (1-X)64.9278
where X is the decimal precent of Cu63, and 1-x is the decimal percent of Cu65

Answer 2

I am not understand