A radioactive isotope decays at the rate indicated by the exponential function ,where 't' is the time in year and A(t) is the amount of the isotope, in grams, remaining. How long will it take for the isotope to be reduced to half of its original amount?

Simplify the expression 10/11(22z) + (a+5) -1

How is working backward similar to solving an equation?

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?