This is an incomplete question, here is a complete question.
Manganese commonly occurs in nature as a mineral. The extraction of manganese from the carbonite mineral rhodochrosite, involves a two-step process. In the first step, manganese (II) carbonate and oxygen react to form manganese (IV) oxide and carbon dioxide:

In the second step, manganese (IV) oxide and aluminum react to form manganese and aluminum oxide:

Write the net chemical equation for the production of manganese from manganese (II) carbonate, oxygen and aluminum. Be sure your equation is balanced.
Answer : The net chemical equation for the production of manganese is:

Explanation :
The given two chemical reactions are:
(1) 
(2) 
First we are multiplying reaction 1 by 3, and reaction 2 by 2, we get:
(1)
(2) 
Now we are adding both the reactions, we get the overall chemical reaction.

The
is common on both side, by cancelling it, we get:
The net chemical equation for the production of manganese is:
