Verify that parallelogram abcd with vertices a(–5, –1), b(–9, 6), c(–1, 5), and d(3, –2) is a rhombus by showing that it is a parallelogram with perpendicular diagonals.

Out of 50 students surveyed, 16 have a dog. based on these results, predict how many of the 280 students in the school have a dog.

What is the the greatest common factor ?

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?