Answer:
[tex]-6Br^2-18r+Br+3[/tex]
Step-by-step explanation:
we have the expression:
[tex](6r-1)(- Br-3)[/tex]
We need to multiply the two terms in the first parenthesis by the two terms in the second parenthesis:
[tex](6r)(-Br)+(6r)(-3)+(-1)(-Br)+(-1)(-3)[/tex]
we solve each term taking into account the law of signs
(-)(-)=+
and
(+)(-)=-
also for the first term we use that [tex]r*r=r^2[/tex]
thus we have:
[tex]-6Br^2-18r+Br+3[/tex]
it can be simplified a little more if we factor an r of the second and third term:
[tex]-6Br^2+r(-18+B)+3[/tex]
