<u>Answer:</u>
<u>For a:</u> The balanced equation is 
<u>For c:</u> The balanced equation is 
<u>Explanation:</u>
A balanced chemical equation is one where all the individual atoms are equal on both sides of the reaction. It follows the law of conservation of mass.
The given unbalanced equation follows:

To balance the equation, we must balance the atoms by adding 2 infront of both
and
and 3 in front of 
For the balanced chemical equation:

The given balanced equation follows:

The given equation is already balanced.
The given unbalanced equation follows:

To balance the equation, we must balance the atoms by adding 2 infront of 
For the balanced chemical equation:
The given balanced equation follows:

The given equation is already balanced.