Question 924971
Sure
Let x=amount of pure copper needed
Now we know that the amount of pure copper that exists  before the mixture takes place (x+0.12*34) has to equal the amount of pure copper that exists after the mixture takes place (0.32*(34+x)). Soooo our equation to solve is:
x+0.12*34=0.32(34+x)
You solve

Hope this helps---ptaylor