The linear combination method gives a solution of (–4, 2) for which of these systems of linear equations?
3 x + 13 y = 14. 6 x + 11 y = negative 2.
4 x + 5 y = 12. 8 x + 3 y = negative 4.
5 x + 4 y = 12. 7 x + 8 y = 12.
10 x + 3 y = 8. 17 x + 6 y = 10.

Amachine that produces a special type of transistor (a component of computers) has a 2% defective rate. the production is considered a random process where each transistor is independent of the others. (a) what is the probability that the 10th transistor produced is the first with a defect? (b) what is the probability that the machine produces no defective transistors in a batch of 100? (c) on average, how many transistors would you expect to be produced before the first with a defect? what is the standard deviation? (d) another machine that also produces transistors has a 5% defective rate where each transistor is produced independent of the others. on average how many transistors would you expect to be produced with this machine before the first with a defect? what is the standard deviation? (e) based on your answers to parts (c) and (d), how does increasing the probability of an event a↵ect the mean and standard deviation of the wait time until success?