If the roots of $x^3-9x^2+kx+l=0$  are in A.P with common difference 2 then $\left(k,l\right)=$

Given roots are in A.P and $d=2$

$a-d,a,a+d$

$a-d+a+a+d=9$

$a=3$

Substitute $\text{'}a\text{'}$  in $f\left(x\right)$

$27-81+3k+l=0$

$3k+l=54\cdots \cdots \cdots \left(1\right)$

$\left(a^2-d^2\right)\left(a\right)=-l$

$l=-15$

Substitute l in $\left(1\right)$

$3k+l=54$

$3k=69\Rightarrow k=23$

$\therefore \left(k,l\right)=\left(23,-15\right)$