(1 + 5) + 9 = 15 another way to right this

Ab and bc form a right angle at point b. if a= (-3,-1) and b= (4,4) what is the equation of bc?

Type the correct answer in each box. spell all the words correctly, and use numerals instead of words for numbers. if necessary, use / for the fraction bar(s).

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?