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3 years ago

What is being distributed in the following problem? 5 - 31d + 7)

Mathematics

1 answer:

USPshnik [31]3 years ago

7 0

Answer:

the -3 is being distributed. --> the 5 stays outside till the end. multiply the 3 inside first, then the negative. and then add the 5 to the final answer

5-3(d+21) = -->> 5-(3d+21)=--->>>5-3d-21=3d-16

Step-by-step explanation:

5-3(d+21) =

5-(3d+21)=

5-3d-21=

ans=3d-16

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Dy/dx = 2xy^2 and y(-1) = 2 find y(2)

Anarel [89]

If you're using the app, try seeing this answer through your browser: brainly.com/question/2887301

—————

Solve the initial value problem:

dy
——— = 2xy², y = 2, when x = – 1.
dx

Separate the variables in the equation above:

$\mathsf{\dfrac{dy}{y^2}=2x\,dx}\\\\
\mathsf{y^{-2}\,dy=2x\,dx}$

Integrate both sides:

$\mathsf{\displaystyle\int\!y^{-2}\,dy=\int\!2x\,dx}\\\\\\
\mathsf{\dfrac{y^{-2+1}}{-2+1}=2\cdot \dfrac{x^{1+1}}{1+1}+C_1}\\\\\\
\mathsf{\dfrac{y^{-1}}{-1}=\diagup\hspace{-7}2\cdot \dfrac{x^2}{\diagup\hspace{-7}2}+C_1}\\\\\\
\mathsf{-\,\dfrac{1}{y}=x^2+C_1}$

$\mathsf{\dfrac{1}{y}=-(x^2+C_1)}$

Take the reciprocal of both sides, and then you have

$\mathsf{y=-\,\dfrac{1}{x^2+C_1}\qquad\qquad where~C_1~is~a~constant\qquad (i)}$

In order to find the value of C₁ , just plug in the equation above those known values for x and y, then solve it for C₁:

y = 2, when x = – 1. So,

$\mathsf{2=-\,\dfrac{1}{1^2+C_1}}\\\\\\
\mathsf{2=-\,\dfrac{1}{1+C_1}}\\\\\\
\mathsf{-\,\dfrac{1}{2}=1+C_1}\\\\\\
\mathsf{-\,\dfrac{1}{2}-1=C_1}\\\\\\
\mathsf{-\,\dfrac{1}{2}-\dfrac{2}{2}=C_1}$

$\mathsf{C_1=-\,\dfrac{3}{2}}$

Substitute that for C₁ into (i), and you have

$\mathsf{y=-\,\dfrac{1}{x^2-\frac{3}{2}}}\\\\\\
\mathsf{y=-\,\dfrac{1}{x^2-\frac{3}{2}}\cdot \dfrac{2}{2}}\\\\\\
\mathsf{y=-\,\dfrac{2}{2x^2-3}}$

So y(– 2) is

$\mathsf{y\big|_{x=-2}=-\,\dfrac{2}{2\cdot (-2)^2-3}}\\\\\\
\mathsf{y\big|_{x=-2}=-\,\dfrac{2}{2\cdot 4-3}}\\\\\\
\mathsf{y\big|_{x=-2}=-\,\dfrac{2}{8-3}}\\\\\\
\mathsf{y\big|_{x=-2}=-\,\dfrac{2}{5}}\quad\longleftarrow\quad\textsf{this is the answer.}$

I hope this helps. =)

Tags: <em>ordinary differential equation ode integration separable variables initial value problem differential integral calculus</em>

7 0

3 years ago

Brian bought 4 CDs that were each the same price. Including sales tax, he paid a total of $60.80 . Of that total, $3.60 was tax.

Yuliya22 [10]

Answer:

14.30

Step-by-step explanation:

$60.80 - $3.60 = 57.20/4 = 14.30

3 0

3 years ago

The population of a small town can be described by the equation PN equals 4000+70n. Where n is the number of years after 2005. E

ruslelena [56]

Answer:

The current population (in 2005) is 4000 because it is the constant. The slope tells us how many people are added to the population, so 70 per year. For ex. 2008 (2008- 2005 = 3=> 3 x 70 = 210 => 210 + 4000 = 4210).

8 0

3 years ago

Help:) Factor f(x) = 4x^3+ 23x^2- 70x + 16 into linear factors given that - 8 is a zero of f(x).

Charra [1.4K]

Answer:

(x + 8)(x - 2)(4x - 1)

Step-by-step explanation:

Given that x = - 8 is a zero then (x + 8) is a factor

Divide f(x) by (x + 8) using Synthetic division

- 8 | 4 23 - 70 16

↓ - 32 72 - 16

---------------------------------

4 - 9 2 0

Quotient = 4x² - 9x + 2 = (x - 2)(4x - 1)

Thus

f(x) = (x + 8)(x - 2)(4x - 1)

8 0

3 years ago

Please help. Will give brainliest

natita [175]

I believe C. I’m not completely sure tho...

6 0

3 years ago