SOMEONE PLS HELP ME WITH THIS I DONT UNDERSTAND IT I WILL MARK YOU AS BRAINLIEST IF YOU ANSWER CORRECTLY PLS AND TY​

Which multiplicative property is being illustrated below? (type commutative, associative, or identity) 5 × 2 × 4 = 2 × 5 × 4

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

Solve the system of equations using the substitution method. {y=−3x+7x=−2y−16 enter your answers in the boxes.