Give the property for the missing part of the problem What happened from the first line to the second line?

I'm confused on this could anyone me and show me what i need to do to solve it.

The evening newspaper is delivered at a random time between 5: 30 and 6: 30 pm. dinner is at a random time between 6: 00 and 7: 00 pm. each spinner is spun 30 times and the newspaper arrived 19 times before dinner. determine the experimental probability of the newspaper arriving before dinner.

Factor the polynomial. b^2 + 4b + 4