19q + 48r
Explanation:[tex]3\mleft(q-2r\mright)+6r-8\mleft(-6r-2q\mright)[/tex]Expanding the parenthesis:
[tex]3\mleft(q)-3(2r\mright)+6r-8\mleft(-6r)-8(-2q\mright)[/tex]Multiplication of same sign gives positive number. Multiplication of opposite signs give negative number.
[tex]3q\text{ - 6r + 6r + 48r + 16q}[/tex][tex]\begin{gathered} \text{collect like terms:} \\ 3q\text{ + 16q - 6r + 6r + 48r} \\ 19q\text{ + 48r} \end{gathered}[/tex]