Question 650252
When we have a negative in front of a parentheses, we change ALL of the signs

{{{-(b+1)}}} becomes {{{-b-1}}}

Now we are left with this:

{{{6-b-1=9}}}

We can now move the 6 to the right side of the equation. Don't forget to change the sign:

{{{-b-1=3}}}

Move the -1:

{{{-b=4}}}

Finally, divide each sides of the equation by -1:

{{{b=-4}}}

Hope this helps!

Dr. Sheldon Cooper