Balancing a Redox Equation in Acidic Solution

[pompey]

Homework Statement

Balance the following redox equation (in an acidic solution):

Cu + NO₃^- -> NO₂ + Cu²

The Attempt at a Solution

I got 4H⁺ + 2NO₃^- + Cu -> Cu⁺²+ + 2NO₂ + 2H₂O

But my book told me the same thing, but without the H<sup>2[/sub]O:

4H+ + 2NO₃- + Cu -> Cu+2+ + 2NO₂</sup>

 

[symbolipoint]

Your answer is better because YOURS is balanced. The book's answer, by dropping the water from the right-side is not balanced. Check the number of oxygens on the two sides!