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telo118 [61]
3 years ago
12

How do you find percent of a number mentally

Mathematics
2 answers:
ycow [4]3 years ago
6 0
Percentage of a number using mental math. Learn how to solve percent problems in your head! Since 10% is 1/10, and it's so easy to find 1/10 of any number, we can use that to quickly calculate certain percentages of quantities in our heads. to find 20% of a number, first find 10% of it, and double that.
olga55 [171]3 years ago
5 0
It isn't easy really but you can always divide the number out. For example 50% of 200 is 100 by dividing 200 by 2 or 25% of 100 is 25 by dividing 100 by 4 since 25% is equivalent to 1/4
You might be interested in
. For each of these intervals, list all its elements or explain why it is empty. a) [a, a] b) [a, a) c) (a, a] d) (a, a) e) (a,
Eva8 [605]

Answer:

Elements are of the form

 (i) [a,a]=\{[x,y] : a\leq x\leq a, a\leq y\leq a; a\in \mathbb R\}

(ii) [a,b)=\{[x,y) :a\leq x

(iii)(a,a]=\{(x,y] :a

(iv)(a,a)=\{(x,y): a

(v) (a,b) where a>b=\{(x,y) : a>x>b,a>y>b;a>b,a,b \in \mathbb R\}

(vi) [a,b] where a>b=\{[x,y] : a\geq x\geq b,a\geq y\geq b;a>b,a,b \in \mathbb R\}

Step-by-step explanation:

Given intervals are,

(i) [a,a] (ii) [a,a) (iii) (a,a] (iv) (a,a) (v) (a,b) where a>b (vi)  [a,b] where a>b.

To show all its elements,

(i) [a,a]

Imply the set including aa from left as well as right side.

Its elements are of the form.

\{[a,a] : a\in \mathbb R\}=\{[0,0],[1, 1],[-1,-1],[2,2],[-2,-2],[3,3],[-3,-3],........\}

Since there is a singleton element a of real numbers, this set is empty.

Because there is no increment so if a\in \mathbb R then the set  [a,a] represents singleton sets, and singleton sets are empty so is [a,a].

(ii) [a,a)

This means given interval containing a by left and exclude a by right.

Its elements are of the form.

[ 1, 1),[-1,-1),[2,2),[-2,-2),[3,3),[-3,-3),........

Since there is a singleton element a of real numbers withis the set, this set is empty.

Because there is no increment so if a\in \mathbb R then the set  [a,a) represents singleton sets, and singleton sets are empty so is [a.a).

(iii) (a,a]

It means the interval not taking a by left and include a by right.

Its elements are of the form.

( 1, 1],(-1,-1],(2,2],(-2,-2],(3,3],(-3,-3],........

Since there is a singleton element a of real numbers, this set is empty.

Because there is no increment so if a\in \mathbb R then the set  (a,a] represents singleton sets, and singleton sets are empty so is (a,a].

(iv) (a,a)

Means given set excluding a by left as well as right.

Since there is a singleton element a of real numbers, this set is empty.

Its elements are of the form.

( 1, 1),(-1,-1],(2,2],(-2,-2],(3,3],(-3,-3],........

Because there is no increment so if a\in \mathbb R then the set  (a,a) represents singleton sets, and singleton sets are empty, so is (a,a).

(v) (a,b) where a>b.

Which indicate the interval containing a, b such that increment of x is always greater than increment of y which not take x and y by any side of the interval.

That is the graph is bounded by value of a and it contains elements like it we fixed a=5 then,

(a,b)=\{(5,0),(5,1),(5,2).....\} e.t.c

So this set is connected and we know singletons are connected in \mathbb R. Hence given set is empty.

(vi) [a,b] where a\leq b.

Which indicate the interval containing a, b such that increment of x is always greater than increment of y which include both x and y.

That is the graph is bounded by value of a and it contains elements like it we fixed a=5 then,

[a,b]=\{[5,0],[5,1],[5,2].....\} e.t.c

So this set is connected and we know singletons are connected in \mathbb R. Hence given set is empty.

8 0
3 years ago
Can Someone Please Help Me With This Question. I'll post a picture of the question ​
Vedmedyk [2.9K]

Answer:

y-7=3(x-9)

Step-by-step explanation:

The form of equation of line given in the problem is the point-slope form of a line. That is given by:

y-y_1=m(x-x_1)

We need y_1 and m (denoted by boxes)

y_1 is the y coordinate of the first set of points.

The first coordinate pair is (9,7), so y_1  would be 7

y_1=7

Now, the slope (m).

It has formula

m=\frac{y_2-y_1}{x_2-x_1}

So, x_1 = 9

y_1 = 7

x_2 = 4

y_2 = -8

Substituting, we get the slope to be:

m=\frac{y_2-y_1}{x_2-x_1}\\m=\frac{-8-7}{4-9}\\m=\frac{-15}{-5}\\m=3

Hence, the equation of the line in point-slope is:

y-7=3(x-9)

5 0
3 years ago
fruit-o-rama sells dried pineapple forn 0.25 per ounce.mags spent a total of 2.65 on pineapple. how many ounces did she buy
Scrat [10]
10.6 ounces I believe
4 0
3 years ago
Which of these is a synonym of 'closing sentence"? *
Sophie [7]

Answer:

conclusion because you are concluding eveything you said in the paragraph before.

4 0
3 years ago
Two numbers have a difference of 0.85 and a sum of 1 what are the numbers?
soldier1979 [14.2K]
X - y = 0.85
x + y = 1
----------------add
2x = 1.85
x = 1.85/2
x = 0.925

x + y = 1
0.925 + y = 1
y = 1 - 0.925
y = 0.075

so ur 2 numbers are : 0.925 and 0.075
3 0
3 years ago
Read 2 more answers
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