If

${\displaystyle \underset{-7}{\overset{6}{}}}y(s)ds=15$

${\displaystyle \underset{-1}{\overset{6}{}}}y(s)ds=9\mathrm{.}3$

what does the following integral equal?

${\displaystyle \underset{-7}{\overset{-1}{}}}y(s)ds=$