Thien and her friends earned $80 washing cars. Thien received $30 from this amount. What is Thien's share as a percentage of the total amount earned?

Does anyone know how to solve and graph this: 4 + | a + 2 | < 7the only part i don't get is the "4 +"

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?

Acircle has a radius of 12.6cm what is the exact length of an arc formed by a central angle measuring 120