Chemistry
posted by Laila .
The element copper, found in nature with an average atomic mass of 63.54u, consists of two isotopes, copper63 of atomic mass 62.93u and copper65 of atomic mass 64.93u. Calculate the abundance of each isotope.
I can't come up with an equation to solve it; can someone please help with this?

62.93*(x) + 64.93*(1x) = 63.54
where x is decimal equivalent for that isotope and 1x for the other isotope. 
Let the fraction of Copper65 = x.
Then Copper63 would be (1x)
We set up an equation for the "weighted average" of copper based on the individual isotopes of copper:
62.93(1x) + 64.93x = 63.54
Solve for x to get the % of Cu63
Use (1x) to get the % of Cu65 
oh ok, I solved it, thank you very much! :]