How to find the Laplace transform of $f(t\pm a)$?

I am trying to find the laplace transform of $f(t\pm a)$. I did the integration myself and stopped at this point

$${e}^{\pm as}[{\int}_{\pm a}^{0}{e}^{-sk}f(k)dk+{\int}_{0}^{\mathrm{\infty}}{e}^{-sk}f(k)dk]$$

which gives rise to this term

$${e}^{\pm as}[{\int}_{\pm a}^{0}{e}^{-sk}f(k)dk+F(s)]$$

Where $L[f(t)]=F(s)$ and $t\pm a=k$

I couldn't figure out the value of this term

$${\int}_{\pm a}^{0}{e}^{-sk}f(k)dk$$

I am trying to find the laplace transform of $f(t\pm a)$. I did the integration myself and stopped at this point

$${e}^{\pm as}[{\int}_{\pm a}^{0}{e}^{-sk}f(k)dk+{\int}_{0}^{\mathrm{\infty}}{e}^{-sk}f(k)dk]$$

which gives rise to this term

$${e}^{\pm as}[{\int}_{\pm a}^{0}{e}^{-sk}f(k)dk+F(s)]$$

Where $L[f(t)]=F(s)$ and $t\pm a=k$

I couldn't figure out the value of this term

$${\int}_{\pm a}^{0}{e}^{-sk}f(k)dk$$