Select the correct answer. The elimination method is ideal for solving this system of equations. By which number must you multiply the second equation to eliminate the y-variable, and what is the solution for this system?

x + 3y = 42
2x − y = 14

A.
Multiply the second equation by -3. The solution is x = 12, y = 9.
B.
Multiply the second equation by -2. The solution is x = 12, y = 10.
C.
Multiply the second equation by 2. The solution is x = 15, y = 9.
D.
Multiply the second equation by 3. The solution is x = 12, y = 10.

Given f(x)= 9x+1 and g(x)=x^3, choose the expression (f*g)(x)

The pyramid below was dissected by a horizontal plane which shape describes the pyramid horizontal cross section

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?