Shelly and terrence completed a different number of tasks in a game. shelly earned 90 points on each task. terrence's total points were 20 less than shelly's total. the expression below shows terrence's total points in the game: 90x − 20 what does the factor x of the first term of the expression represent?

Assume that there is a 11% rate of disk drive failure in a year. a. if all your computer data is stored on a hard disk drive with a copy stored on a second hard disk drive, what is the probability that during a year, you can avoid catastrophe with at least one working drive? b. if copies of all your computer data are stored on four independent hard disk drives, what is the probability that during a year, you can avoid catastrophe with at least one working drive?