Ax + 3y = 10 kx - 3y = 6
In the system of equations above, a and k are constants. If the solution to the system is (2, 1), what is the value of a + k?
А 30
B 8
C 2
D -2

Suppose that 3% of all athletes are using the endurance-enhancing hormone epo (you should be able to simply compute the percentage of all athletes that are not using epo). for our purposes, a “positive” test result is one that indicates presence of epo in an athlete’s bloodstream. the probability of a positive result, given the presence of epo is .99. the probability of a negative result, when epo is not present, is .90. what is the probability that a randomly selected athlete tests positive for epo? 0.0297