Me pueden ayudar a resolver por método de sustitución porfa.
{5x+7y=-1
{-3x+4y=-24

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

Astore ordered 750 candles a total wholesale cost of $7910.20. the soy candles cosy $12.17 each and thespecialty candles cost $9.58each. how many of each were bought?

In δabc, m∠acb = 90°, cd ⊥ ab and m∠acd = 45°. find: a find cd, if bc = 3 in