I REALLY NEED HELP ASAP

What signals you that factoring by grouping is the best method to use when factoring a problem?

The human resources manager at a company records the length, in hours, of one shift at work, x. he creates the probability distribution below. what is the probability that a worker chosen at random works at least 8 hours? probability distribution px(x) 6 hours 7 hours 8 hours 9 hours 10 hours 0.62 0.78 пол

From the beginning of the day the temperature rose 15 degrees so that by 4 pm it was 87 degrees. what was the temperature at the start of the day