Question

FE(NO3)2+NA2CO3----> balance
c7h16+02-----> balance

Answer 1

the first reaction is a double displacement reaction, which always has the same general form:\[AB + CD \rightarrow AD + CB\] You've got to make sure the products balance each otehr for charge before trying to balance the reaction.
The second reaction is a combustion reaction, which always produces the same 2 things: CO2 and water\["fuel" + O{_2} \rightarrow CO{_2} + H{_2}O\] balance C and H first. \[C_{7}H_{16} + 11 O_{2} rightarrow 7CO_{2} + 8H_{2}O\]