Stein equation. A Stein equation with respect to square matrix X has the form AXB-X+Q = 0, where A. B and Q are constant square matrices. (a) When does this equation have a unique solution? (b) Figure out all solutions in case of A [] B= 12 -4 (c) Construct a counter example in which no solution exists.

Let's say the countdown for a space shuttle launch has begun. At "T minus 25 hours" (that is, 25 hours before launch), a problem occurs. If the technicians have not fixed the problem by T minus 8 hours, the launch will have to be scratched. How much time (in hours) do the technicians have to correct the problem? hr

Show all steps to add: 1/(x-4) + -5/(x+4)