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3 years ago

Pls help. No files pls. Will give brainliest.

Mathematics

1 answer:

nordsb [41]3 years ago

6 0

To find f(-20), first figure out which piece x = -20 fits with.

Since -20 < -12, x = -20 first in the domain used by the third piece.

For f(-20), treat this function as if it was just f(x) = 3x-7.

f(-20) = 3(-20) -7

= -60 - 7

= -67

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Someone please help me

kap26 [50]

Answer:

The answer is x = 4

Step-by-step explanation:

1. First you need to distribute the 3/4 * (x + 8). This looks like (3/4) * (x) + (3/4) * (8) = 9

2. Next you simplify the distributed equation, 3/4x + 6 = 9

3. Now subtract 6 from both sides, 3/4x = 3

4. Multiply both sides by 4/3, 4/x * 3/4x = 3 * 4/3

5. Simplify, x = 4

8 0

3 years ago

use the general slicing method to find the volume of The solid whose base is the triangle with vertices (0 comma 0 ), (15 comma

lyudmila [28]

Answer:

volume V of the solid

$\boxed{V=\displaystyle\frac{125\pi}{12}}$

Step-by-step explanation:

The situation is depicted in the picture attached

(see picture)

First, we divide the segment [0, 5] on the X-axis into n equal parts of length 5/n each

[0, 5/n], [5/n, 2(5/n)], [2(5/n), 3(5/n)],..., [(n-1)(5/n), 5]

Now, we slice our solid into n slices.

Each slice is a quarter of cylinder 5/n thick and has a radius of

-k(5/n) + 5 for each k = 1,2,..., n (see picture)

So the volume of each slice is

$\displaystyle\frac{\pi(-k(5/n) + 5 )^2*(5/n)}{4}$

for k=1,2,..., n

We then add up the volumes of all these slices

$\displaystyle\frac{\pi(-(5/n) + 5 )^2*(5/n)}{4}+\displaystyle\frac{\pi(-2(5/n) + 5 )^2*(5/n)}{4}+...+\displaystyle\frac{\pi(-n(5/n) + 5 )^2*(5/n)}{4}$

Notice that the last term of the sum vanishes. After making up the expression a little, we get

$\displaystyle\frac{5\pi}{4n}\left[(-(5/n)+5)^2+(-2(5/n)+5)^2+...+(-(n-1)(5/n)+5)^2\right]=\\\\\displaystyle\frac{5\pi}{4n}\displaystyle\sum_{k=1}^{n-1}(-k(5/n)+5)^2$

But

$\displaystyle\frac{5\pi}{4n}\displaystyle\sum_{k=1}^{n-1}(-k(5/n)+5)^2=\displaystyle\frac{5\pi}{4n}\displaystyle\sum_{k=1}^{n-1}((5/n)^2k^2-(50/n)k+25)=\\\\\displaystyle\frac{5\pi}{4n}\left((5/n)^2\displaystyle\sum_{k=1}^{n-1}k^2-(50/n)\displaystyle\sum_{k=1}^{n-1}k+25(n-1)\right)$

we also know that

$\displaystyle\sum_{k=1}^{n-1}k^2=\displaystyle\frac{n(n-1)(2n-1)}{6}$

and

$\displaystyle\sum_{k=1}^{n-1}k=\displaystyle\frac{n(n-1)}{2}$

so we have, after replacing and simplifying, the sum of the slices equals

$\displaystyle\frac{5\pi}{4n}\left((5/n)^2\displaystyle\sum_{k=1}^{n-1}k^2-(50/n)\displaystyle\sum_{k=1}^{n-1}k+25(n-1)\right)=\\\\=\displaystyle\frac{5\pi}{4n}\left(\displaystyle\frac{25}{n^2}.\displaystyle\frac{n(n-1)(2n-1)}{6}-\displaystyle\frac{50}{n}.\displaystyle\frac{n(n-1)}{2}+25(n-1)\right)=\\\\=\displaystyle\frac{125\pi}{24}.\displaystyle\frac{n(n-1)(2n-1)}{n^3}$

Now we take the limit when n tends to infinite (the slices get thinner and thinner)

$\displaystyle\frac{125\pi}{24}\displaystyle\lim_{n \rightarrow \infty}\displaystyle\frac{n(n-1)(2n-1)}{n^3}=\displaystyle\frac{125\pi}{24}\displaystyle\lim_{n \rightarrow \infty}(2-3/n+1/n^2)=\\\\=\displaystyle\frac{125\pi}{24}.2=\displaystyle\frac{125\pi}{12}$

and the volume V of our solid is

$\boxed{V=\displaystyle\frac{125\pi}{12}}$

3 0

3 years ago

Help please :) about to post more too

yKpoI14uk [10]

Answer:

Lets say test tubes = t, and beakers = b

1 pack of (t) is $4 less than 1 pack of (b)

Since i have no prior information we are going to use variables for this equation:

1t (1 pack of test tubes) is $4 less than 1b (1 set of beakers)

so to quantify the equation, we have 8t and 12b.

if b is a number that IS quantifiable such as $5 we can easily figure out this answer.

Lets use and example that 1 set of beakers is $8, if we multiply $8 by 12 (the number of sets of beakers), we get: 96

Using the same example, if 1t is $4 less than 1b than 1t = $4. So, if we multiply $4 by 8 (the amount of packs of test tubes), we get: 32

If you take both of those numbers: 96, and 32 and you divide them you get 3. so that means that 1t = 3b

Answer = 1t = 3b

This may not be correct due to the little information that i got however i hope that, that works out for you :)

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3 years ago

What is two and two thirds plus one and one half

Yuki888 [10]

the answer it four and one sixths

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3 years ago

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What's 300000+49498383837?

tatuchka [14]

49498683837. To work these questions out, use column addition, it is a quick and simple way to add large numbers.

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3 years ago

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