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RSB [31]
2 years ago
13

1.What must be used to tell if a collection of items is a set?

Mathematics
1 answer:
Mnenie [13.5K]2 years ago
3 0
1. A set is described either by listing all its elements between braces { } (the listing method), or by enclosing a rule within braces that determines the elements of the set (the rule method).
Example: So if P(x) is a statement about x, then S = { x | P ( x )} means “S is the set of all x such that P(x) is true.”

2. Types of set:
• Empty, or null, set {∅}.
• finite sets
• infinite set.

3. An infinite set: The set whose elements cannot be listed, i.e., set containing never-ending elements. Example: Set of all points in a plane.

4. The union of two given sets is the smallest set which contains all the elements of both the sets. To find the union of two given sets A and B is a set which consists of all the elements of A and all the elements of B such that no element is repeated. The symbol for denoting union of sets is ‘∪’.

The union of sets A and B, denoted by A ∪ B, is the set of elements formed by combining all the elements of A and all the elements of B into one set.
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What is the slope of a line whose graph is parallel to the graph of -3x+y=2?
liq [111]

Answer:

Step-by-step explanation:

if the lines are parallel they have the same gradient.

rearrange the equation to make y the subject and then use the m value as gradient.

-3x=2-y

-3x-2=-y

y=-(-3x-2)

y=3x+2

therefore m=3

slope is 3

7 0
2 years ago
If 18 is subtracted from twice the square of an integer, the
Sergeu [11.5K]

Answer:

-3/2

Step-by-step explanation:

Let x = the integer:

2x^2 - 18 = 9x

2x^2 - 9x - 18 = 0

Now either factor that or use the quadratic formula if you're lazy like me.

x = -3/2 and 6, so x must be 6 because it has to be an integer.

5 0
2 years ago
Kayla and Camille, both teachers, are adding books to their class libraries. Kayla’s classroom started out with a collection of
Airida [17]
34
because, 34 = 14 + (10 x 2)
and 34 = 24 + (10 x 1)
4 0
3 years ago
Which is a factor of 144 - 49x²?<br> O 12-7x²<br> O 72-7x²<br> O 12-7x<br> O 72 + 7x
lisabon 2012 [21]

Answer: C: 12-7x

Step-by-step explanation:

This expression is a good example of the difference of two squares, as 144 is the square of 12, while 49x² is the square of 7x.

Any difference of two squares a^2-b^2 can be factored into the sum of their square roots times the difference of their square roots (a+b)(a-b).

Let's factor our expression.

144-49x^2=(12+7x)(12-7x)

Out of all the options given, only 12-7x is a factor. Hence, option C is correct.

4 0
2 years ago
Find the area of the trapezoid.
ss7ja [257]

\bf \textit{area of a trapezoid}\\\\&#10;A=\cfrac{h(a+b)}{2}~~&#10;\begin{cases}&#10;a,b=\stackrel{bases}{parallel~sides}\\&#10;h=height\\[-0.5em]&#10;\hrulefill\\&#10;a=15.8\\&#10;b=21.8\\&#10;h=11.7&#10;\end{cases}\implies A=\cfrac{11.7(15.8+21.8)}{2}&#10;\\\\\\&#10;A=\cfrac{11.7(37.6)}{2}\implies A=219.96

4 0
3 years ago
Read 2 more answers
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