a+b−(2c+b)=? a+b-(2c+b)=\text{?} a+b−(2c+b)=?
First, we open the parentheses and change the sign accordingly.
Since there are only positive numbers inside the parentheses, multiplying by negative will give us negative numbers:
a+b−2c−b= a+b-2c-b= a+b−2c−b=
Now we group the b factors:
b−b=0 b-b=0 b−b=0
Now we obtain:
a−2c a-2c a−2c