When A reacts with B$,$ the reaction produces C and D $($reaction $1)$:

$A_{(s)}+3B_{(l)}-C_{(l)}+2D_{(s)}$

But when A reacts with $C,$ the reaction produces $B$ and $D($reaction $2)$:

$2A_{(s)}+3C_{(l)}{B}_{(l)}+D_{(s)}$

The heat of formation $($at standard state$)$ for $A_{(s)}$ is not available in any literature; however, the heat of formation $($at standard state$)$ for B$,$ C$,$ and D is available:

$B_{(l)}=950k\frac{j}{m}ol$

$C_{(l)}=800k\frac{j}{m}ol$

$D_{(s)}=-200$kj$/$mol

Experiment shows that the heat of reaction of reaction $2$ is thrice the amount of the heat of reaction of reaction $1($say$,$ heat of reaction of reaction $2$ is $9,$ therefore, heat of reaction of reaction $1$ is $3).$

Determine the heat of formation $($at standard state$)$ of $A_{(s)}($in $kJ/$mol$).$