There are two ways of describing, or specifying the members of, a set. One way is by intensional definition, using a rule or semantic description: The second way is by extension - that is, listing each member of the set. An extensional definition is denoted by enclosing the list of members in curly brackets:
You can make 125 different 3-digit numbers if you're allowed to repeat a digit (for example, 113, or 545), and 60 if you're not. If repetitions are allowed, then there are 5 ways to choose each digit to be 1,2,3,4, or 5, so the total number of ways is 5*5*5 or 125. If no repetitions are allowed, there are 5 ways to choose the first digit, but only 4 ways left to choose the second (for a total of 5*4=20 ways to choose the first two digits), because it can't be the same as the first. Then you have eliminated two choices for the third digit, so there are only 3 ways to choose it, for a total of 5*4*3=60 different 3-digit numbers.
The empty set is a subset of all sets. No other sets have this property.
The set of all real numbers (R) is the set of all rational and irrational numbers. The set R has no restrictions in its domain and so includes (-∞, ∞).
6x-3y=30 4x=2-y There are many ways to find the values of x and y. elimination substitution matrices on and on... Here's one. Set them both equal to y y=2x-10 y=2-4x So the right sides are both equal to y, therefore, they are equal to each other. 2x-10 = 2-4x 6x=12 x=2 plug 2 in for x on one of the equations y=2-4x y=2-4(2) y=-6
the ways in naming a set are: roster method, rule method and set builders
the other one is intersection
rosting method rule method set-builder rotation
It is called creating or naming a set!
One way is with curly brackets, for instance {3,4,5,6,7,8}. Another way to name this set would be {(x is a natural number)intersection(3<=x<=8)}
method of concerning
method of concerning
Roster Method, for example {1, 2, 3, 4,5, 6} Set builder, for example {x:x is an element of Natural numbers, x
no
One way is with curly brackets, for instance {3,4,5,6,7,8}. Another way to name this set would be {(x is a natural number)intersection(3<=x<=8)}
poster method,set builder,descriptive
trv 7words ok