What is n(A) and n(B) in sets lesson?

Set membership x ∈ X means x is an element of the set X. ... The set of natural numbers N has elements 0,1,2,3, Intersection X ∩ Y is defined by: x ∈ X ∩ Y if and only if x ∈ X and x ∈ Y .

the difference between a number and 5 is -2.

step-by-step explanation:

notice that the equation you are given has -2 (negative 2) on the right side, not 2. when you subtract 5 from a number n, you are finding the difference between the number and 5.

the difference between a number and 5 is -2.

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)