I need this math equation simplified.

Leo has b boxes of pencils. each box contains 6 pencils. he has a total of 42 pencils. the equation that represents this situation the value of b that makes the equation true the first one is b+6=42,6b=42,b=42+6,or 42b=6 the second one are 7,836 48

How can constraints be used to model a real-world situation?

What is the mean of the data set 125, 141, 213, 155, 281