$(16$ points$)$ Use the form $of$ the definition $of$ the integral $to$ evaluate

${\displaystyle \underset{1}{\overset{3}{}}}(6-5x)dx$

Feel free $to$ use Example $5\mathrm{.}8in$ the Class Notes $as$ a guide for this problem. Ensure that all appropriate language and

steps are included, legible, and organized when writing proofs $to$ earn full credit. $To$ earn full credit, students need

$to$ define $x$ and $x_i,$ use sigma notation, $limits,$ the properties $of$ sigma notation, and sums and powers $of$ integers.