The fact I'm doing all my work but my teacher isn't grading it so i have a b now

Complete the solution of the equation. find the value of y when x equals to 6 4x+y=20

Find the unit rate for: 75% high-fiber chimp food to 25% high -protein chimp food.

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?