-5(-2b-1)
Collect like terms and simplify
(Multiply the number outside the bracket with the ones in the parentheses/bracket)
(-x-)= +
(+x+)= +
(-x+)= -
(+x-)= -
Basically same signs multiplied = +
Different signs multiplied = -
-5(-2b)= 10b
-5(-1)=5
10b+5 is your answer
