Use an operation or a property to justify each step and indicate if the expressions are equivalent -2.1(3.7x - 4) + 0.5(4x - 1) and -5.77x + 7.9​ please I give anyone who give me right answer the brainiest

Solve the system of equations. y= 2x y= x^2 - 15

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

Acomputer store buys a computer system at a cost of $370.80. the selling price was first at $ 618, but then the store advertised a 20 % markdown on the system. answer parts a and b. a. find the current sale price.