Question

Can somebody please balance this !?!

Answer 1

$\mathrm{CO}_2$ has 2 oxygens for every carbon. $\mathrm{CO}$ will contribute one of each for every molecule. You then have to have an even multiple of $\mathrm{CO}$ molecules to not end up with an odd number of oxygens.

So if you take $2\mathrm{CO}$, you should end up with 2 carbons on the RHS. $2\mathrm{CO}_2$ then has 4 oxygens. 2 of them are already accounted for, so you just need one $\mathrm O_2$ to balance out the reaction.

$1\mathrm O_2+2\mathrm{CO}\Rightarrow2\mathrm{CO}_2$

Answer 2

O2 + 2CO = 2CO2. That should be it