Alrighty :) so...
Sodium carbonate is: Na2CO3
Hydrochloric acid is: HCl
This is a double displacement reaction, so the cations and anions are basically going to swap here.
Keep in mind we have the cations: Na(+) and H(+)
And the anions: CO3(-2) and Cl(-)
So we get: Na2CO3 + HCl --> NaCl + H2CO3
Now note that the problem says that our products need to be CO2, H2O, and NaCl.
This might be the tricky part, but it seems like you just have to know that H2CO3 breaks down into H2O + CO2.
H2CO3 --> H2O + CO2
So putting it all together, we get:
Na2CO3 + HCl --> NaCl + H2O + CO2
BUT IS THIS EQUATION BALANCED? We have 2 Na on the left, but 1 Na on the right. We have 1 H on the left, but 2 H on the right...
So after balancing it you should get this:
Na2CO3 + 2HCl --> 2NaCl + H2O + CO2
I'm assuming that you do not need a net ionic equation for this problem and that later on you will use the 1.5M concentrations to solve for some unknown amount.
Lastly, do not forget the states of matter that the problem asks for:
Na2CO3(aq) + 2HCl(aq) --> 2NaCl(aq) + H2O(l) + CO2(g)
Hope this helps, make sure the numbers are the right size! Numbers to the right of an element should be small (subscript) while numbers to the left are normal sized.