Posted by help on .
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

physical science 8th grade 
bobpursley,
63.546=X*62.9298+ (1X)64.9278
where X is the decimal precent of Cu63, and 1x is the decimal percent of Cu65 
physical science 8th grade 
Amanuel fekadu,
I am not understand