Guys i really need help in these three problems. If someone could explain how to do this i would appreciate it!

Question

complete and balance the following equations

1. SO3^2- + Cu^2+ --> SO4^2- + Cu^+
2. Cr +Cu^2+ ---> CrO4^2- + Cu^+
3. MnO2 + Ag^+ ---> MnO4^- + Ag

Answer 1

Here is a web site that tells you how to do this. To balanced these you need
1. how to determine the oxidation state of elements.
2. how to determine the loss and gain of electrons.
3. the system for balancing half equations.
4. how to add the oxidation half to the reduction half.
http://www.chemteam.info/Redox/Redox.html