7. use an "element argument" (that is, the direct proof approach in set theory, where you use a particular but arbitrarily chosen element) to prove the following statements for any sets a and b: (a) a c b b"-ac (b) (a-b) u (b-a) u (a b) =aub

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step-by-step explanation:

the two may have that, even a breakdown is probably offered

0.02

step-by-step explanation:

time of 9 192 631 770 periods of the radiation corresponding to the transition between the 2 hyperfine levels of the ground state of the caesium 133 atom at 0 k (but other seconds are sometimes used in astronomy)