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2 years ago

Hey guys I need help

Mathematics

1 answer:

Gemiola [76]2 years ago

7 0

Answer:

20.8

Step-by-step explanation:

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I have no idea how to do this, so if someone could at least do one of these I’ll be grateful <3

jenyasd209 [6]

Answer:

Answers are below!

Step-by-step explanation:

(2 + g) (8)

= (2 + g) (8)

Add a 8 after the 2, and flip.

= (2)(8) + (g)(8)

= 16 + 8g

= 8g + 16

= (4) (8 + -5g)

Add another 4, then flip.

= (4) (8) + (4) (-5g)

= 32 − 20g

= - 20g + 32

−7 (5-n)

= (−7) (5 + -n)

Add another 7, then flip.

= (−7) (5) + (-7) (-n)

= −35 + 7n

= 7n - 35

Use the distributive property.

a (b + c) = ab + ac

a = 8

b = 2m

c = 1

= 8 × 2m + 8 × 1

Simplify, you get 16m + 8.

Use the distributive property.

a (b + c) = ab + ac

a = 6x

b = y

c = z

= 6xy - 6xz is the answer.

$\mathrm{Apply\:the\:distributive\:law}:\quad \\\:a\left(b+c\right)=ab+ac$

$a=-3,\:b=2b,\:c=2a$

$=-3\cdot \:2b+\left(-3\right)\cdot \:2a$

Apply minus plus rules.

$=-3\cdot \:2b+\left(-3\right)\cdot \:2a$

Multiply the numbers.

3 x 2 = 6

7 0

2 years ago

Read 2 more answers

True or false: the Pythagorean theorem can be applied to every triangle

Mnenie [13.5K]

Answer:

False

Step-by-step explanation:

The Pythagorean theorem can only be applied to right triangles.

4 0

2 years ago

Read 2 more answers

Consider the following. (A computer algebra system is recommended.) y'' + 3y' = 2t4 + t2e−3t + sin 3t (a) Determine a suitable f

drek231 [11]

First look for the fundamental solutions by solving the homogeneous version of the ODE:

$y''+3y'=0$

The characteristic equation is

$r^2+3r=r(r+3)=0$

with roots $r=0$ and $r=-3$ , giving the two solutions $C_1$ and $C_2e^{-3t}$ .

For the non-homogeneous version, you can exploit the superposition principle and consider one term from the right side at a time.

$y''+3y'=2t^4$

Assume the ansatz solution,

${y_p}=at^5+bt^4+ct^3+dt^2+et$

$\implies {y_p}'=5at^4+4bt^3+3ct^2+2dt+e$

$\implies {y_p}''=20at^3+12bt^2+6ct+2d$

(You could include a constant term <em>f</em> here, but it would get absorbed by the first solution $C_1$ anyway.)

Substitute these into the ODE:

$(20at^3+12bt^2+6ct+2d)+3(5at^4+4bt^3+3ct^2+2dt+e)=2t^4$

$15at^4+(20a+12b)t^3+(12b+9c)t^2+(6c+6d)t+(2d+e)=2t^4$

$\implies\begin{cases}15a=2\\20a+12b=0\\12b+9c=0\\6c+6d=0\\2d+e=0\end{cases}\implies a=\dfrac2{15},b=-\dfrac29,c=\dfrac8{27},d=-\dfrac8{27},e=\dfrac{16}{81}$

$y''+3y'=t^2e^{-3t}$

$e^{-3t}$ is already accounted for, so assume an ansatz of the form

$y_p=(at^3+bt^2+ct)e^{-3t}$

$\implies {y_p}'=(-3at^3+(3a-3b)t^2+(2b-3c)t+c)e^{-3t}$

$\implies {y_p}''=(9at^3+(9b-18a)t^2+(9c-12b+6a)t+2b-6c)e^{-3t}$

Substitute into the ODE:

$(9at^3+(9b-18a)t^2+(9c-12b+6a)t+2b-6c)e^{-3t}+3(-3at^3+(3a-3b)t^2+(2b-3c)t+c)e^{-3t}=t^2e^{-3t}$

$9at^3+(9b-18a)t^2+(9c-12b+6a)t+2b-6c-9at^3+(9a-9b)t^2+(6b-9c)t+3c=t^2$

$-9at^2+(6a-6b)t+2b-3c=t^2$

$\implies\begin{cases}-9a=1\\6a-6b=0\\2b-3c=0\end{cases}\implies a=-\dfrac19,b=-\dfrac19,c=-\dfrac2{27}$

$y''+3y'=\sin(3t)$

Assume an ansatz solution

$y_p=a\sin(3t)+b\cos(3t)$

$\implies {y_p}'=3a\cos(3t)-3b\sin(3t)$

$\implies {y_p}''=-9a\sin(3t)-9b\cos(3t)$

Substitute into the ODE:

$(-9a\sin(3t)-9b\cos(3t))+3(3a\cos(3t)-3b\sin(3t))=\sin(3t)$

$(-9a-9b)\sin(3t)+(9a-9b)\cos(3t)=\sin(3t)$

$\implies\begin{cases}-9a-9b=1\\9a-9b=0\end{cases}\implies a=-\dfrac1{18},b=-\dfrac1{18}$

So, the general solution of the original ODE is

$y(t)=\dfrac{54t^5 - 90t^4 + 120t^3 - 120t^2 + 80t}{405}\\\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,-\dfrac{3t^3+3t^2+2t}{27}e^{-3t}-\dfrac{\sin(3t)+\cos(3t)}{18}$

3 0

3 years ago

△PQR≅△DEF, PR=19z−9, and DF=7z+15. Find z and PR.

FrozenT [24]

Answer:

PR=Z=2

Step-by-step explanation:

5 0

2 years ago

Evaluate: 8 - 9+(-2)

Kobotan [32]

Evaluate : 8 - 9 + (-2)

8-9= -1 (because if you take away 9 from 8, you will end up with a negative number since there isn’t enough to take away.)

-1 + -2 = -3 (this is because when you are adding two negative numbers together, you will basically just add -1 and -2 as you would normally, then you would transfer the negative sign as well to make it -3)

Finally, your answer to this question is -3.

5 0

2 years ago