06x + .08 (18000 - x) = 1290 solve for x and explain the steps. x should equal 7500, but i can't figure out how it is done. !

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?

What ia the sum if the first 7 terms of the geometric series

Renting a room at the willow tree resort costs $125 for 2 people. each additional person is $25. write an expression that shows the cost for n extra people