Repeated addition is adding equal groups together. It is also known as multiplication.
The given expression is 4b
Since, 4b show that 4 is multiply by b
Then from the above defination of multiplication:
b is added four times :
i.e.
4b = b + b + b + b
The expanded form of 4b is b + b + b + b
Answer : 4b = b + b + b + b
