What is the enthalpy change related with the reaction of carbon dioxide into its elements?

C$($s$)+$ O$2($g$)->$CO$2($g$)\backslash$Delta Ho total $=?$

$1.$ H$2$O$($l$)->$H$2($g$)+1/2$O$2($g$)\backslash$Delta Ho$1=357\mathrm{.}2$ kJ

$2.$ C$2$H$6($g$)->2$C$($s$)+3$H$2($g$)\backslash$Delta Ho$2=105\mathrm{.}9$ kJ

$3.2$CO$2($g$)+3$H$2$O$($l$)->$ C$2$H$6($g$)+7/2$O$2($g$)\backslash$Delta Ho$3=1950\mathrm{.}6$ kJ