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3 years ago

Suppose that there are 500 students in the school about how many of them study between 4.2 and 5.8

Mathematics

2 answers:

Nata [24]3 years ago

8 0

Answer:

i know right

Step-by-step explanation:

galina1969 [7]3 years ago

6 0

You have to take a poll.

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find the area of the trapezium whose parallel sides are 25 cm and 13 cm The Other sides of a Trapezium are 15 cm and 15 CM

Snezhnost [94]

$\huge\underline{\red{A}\blue{n}\pink{s}\purple{w}\orange{e}\green{r} -}$

Given - A trapezium ABCD with non parallel sides of measure 15 cm each ! along , the parallel sides are of measure 13 cm and 25 cm

To find - Area of trapezium

Refer the figure attached ~

In the given figure ,

AB = 25 cm

BC = AD = 15 cm

CD = 13 cm

Construction -

$draw \: CE \: \parallel \: AD \: \\ and \: CD \: \perp \: AE$

Now , we can clearly see that AECD is a parallelogram !

$\therefore$ AE = CD = 13 cm

Now ,

$AB = AE + BE \\\implies \: BE =AB - AE \\ \implies \: BE = 25 - 13 \\ \implies \: BE = 12 \: cm$

Now , In ∆ BCE ,

$semi \: perimeter \: (s) = \frac{15 + 15 + 12}{2} \\ \\ \implies \: s = \frac{42}{2} = 21 \: cm$

Now , by Heron's formula

$area \: of \: \triangle \: BCE = \sqrt{s(s - a)(s - b)(s - c)} \\ \implies \sqrt{21(21 - 15)(21 - 15)(21 - 12)} \\ \implies \: 21 \times 6 \times 6 \times 9 \\ \implies \: 12 \sqrt{21} \: cm {}^{2}$

Also ,

$area \: of \: \triangle \: = \frac{1}{2} \times base \times height \\ \\\implies 18 \sqrt{21} = \: \frac{1}{\cancel2} \times \cancel12 \times height \\ \\ \implies \: 18 \sqrt{21} = 6 \times height \\ \\ \implies \: height = \frac{\cancel{18} \sqrt{21} }{ \cancel 6} \\ \\ \implies \: height = 3 \sqrt{21} \: cm {}^{2}$

Since we've obtained the height now , we can easily find out the area of trapezium !

$Area \: of \: trapezium = \frac{1}{2} \times(sum \: of \:parallel \: sides) \times height \\ \\ \implies \: \frac{1}{2} \times (25 + 13) \times 3 \sqrt{21} \\ \\ \implies \: \frac{1}{\cancel2} \times \cancel{38 }\times 3 \sqrt{21} \\ \\ \implies \: 19 \times 3 \sqrt{21} \: cm {}^{2} \\ \\ \implies \: 57 \sqrt{21} \: cm {}^{2}$

hope helpful :D

6 0

2 years ago

I really need help would please like help thanks

ASHA 777 [7]

Hey there!

A reciprocal might be an unfamiliar vocab word, but the concept is really quite simple.

It's just a flipped fraction! Multiplying the flipped fraction by it's reciprocal gets you one, and that's how you check your answer.

So we have:

Reciprocal of 9/10 is 10/9, because 9/10 times 10/9 = 90/90 = 1

Reciprocal of 1/11 is 11/1, because 1/11 times 11/1 = 11/11 = 1

Reciprocal of 10(remember, it's 10/1) is 1/10, because 10/1 times 1/10 = 10/10 = 1

Hope this helps!

4 0

3 years ago

How do you find pie?

KiRa [710]

Well pie is 3.14 etc.
And the way to find that out is by:
~Using the formula.
~To find out what the circumference is you have to use this formula
C= π*d =2*π*r
~Pi equals a circle's circumference divided by its diameter.
~If you plug in the numbers in a calculator the numbers should be 3.14.

4 0

3 years ago

Read 2 more answers

I just need answers to the odd numbered questions. I would appreciate the help 35 points

Misha Larkins [42]

Answer:

Step-by-step explanation:

Combine real terms and combine complex terms

1) 3 + 2i + 2 - 5i = 3 +2 + 2i - 5i

= 5 + (2-5)i

= 5 + (-3)i

= 5 - 3i

3) 2 - (1 - 2i) + (4 -5i ) - (1 - 3i) = 2 -1 + 2i + 4 - 5i - 1 + 3i

{- is distributed to (1 - 2i) & - is distributed to (1- 3i)}

= 2 - 1 + 4 + 1 + 2i - 5i + 3i

= 6 +0i = 6

5) 4 - 3i + 4 + 3i = 4 +4 -3i + 3i

= 8

7) (3 - 2i)² + (3 +2i) = 3² - 2*3*2i + (2i)² + 3 + 2i {(a - b)² = a² - 2ab +b²}

= 9 -12i + 4i² + 3 + 2i

= 9 - 12i + 4*(-1) + 3 + 2i {i² = -1}

= 9 +3 - 4 - 12i +2i

= 8 - 10i

$9) (a +b)^{4} - (a - b)^{4} = 8ab(a^{2} +b^{2})\\\\\\Here, \ a = 1 \ and \ b = i\\\\\\(1+\sqrt{-1})^{4}-(1-\sqrt{-1})^{4}=(1+\sqrt{i^{2}})^{4}-(1-\sqrt{i^{2}})^{4}\\\\=(1+i)^{4}-(1-i)^{4}\\\\=8*1*i(1^{2}+i^{2})\\\\=8i*(1 -1)\\\\=8i*0\\\\=0$

6 0

3 years ago

22 divided y equals -2

stepan [7]

22 divided by -2 and you get -11 then 22 divided by -11 = -2

4 0

3 years ago