Select the correct answer. A system of equations and its solution are given below.

System A

To get system B below, the second equation in system A was replaced by the sum of that equation and the first equation in system A multiplied by -2.

System B

A.
The second equation in system B is 7x = 30. The solution to system B will be the same as the solution to system A.
B.
The second equation in system B is -7x = 14. The solution to system B will be the same as the solution to system A.
C.
The second equation in system B is -7x = 14. The solution to system B will not be the same as the solution to system A.
D.
The second equation in system B is 7x = 30. The solution to system B will not be the same as the solution to system A.

How do you determine whether a relationship represented as as graph is linear or nonlinear

You dug a hole that was 8 feet deep. after taking a short break, you dug down 3 more feet in the same hole. when finished digging, a tractor accidentally filled the hole with 4 feet of dirt. how deep is your hole now?

Aprisoner is trapped in a cell containing three doors. the first door leads to a tunnel that returns him to his cell after two days of travel. the second leads to a tunnel that returns him to his cell after three days of travel. the third door leads immediately to freedom. (a) assuming that the prisoner will always select doors 1, 2 and 3 with probabili- ties 0.5,0.3,0.2 (respectively), what is the expected number of days until he reaches freedom? (b) assuming that the prisoner is always equally likely to choose among those doors that he has not used, what is the expected number of days until he reaches freedom? (in this version, if the prisoner initially tries door 1, for example, then when he returns to the cell, he will now select only from doors 2 and 3.) (c) for parts (a) and (b), find the variance of the number of days until the prisoner reaches freedom. hint for part (b): define ni to be the number of additional days the prisoner spends after initially choosing door i and returning to his cell.