I need help with this

Use the elimination method to solve the systems of equations.choose the correct ordered pair. 7x+4y=39

Benjamin is making bow ties. how many 1/2yards lomg bow ties can he make if he has 18 feet of fabric?

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?