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2 years ago

100 POINTS PLEASE HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Mathematics

1 answer:

love history [14]2 years ago

7 0

Answer:

A: 68.25 minutes

B: 12 times

C: 42 mins and you decide this part I actually don't know. But I think it could be reasonable, after 40 times someone should get pretty good at it.

Step-by-step explanation:

a: 72 -0.75*5 = 68.25

b: M=63=72-0.75n

subtract 72 from each side: -9 = -0.75n

divide each side by -0.75: n = 12

so 12 times

c: 72 - 0.75(40) = 42 minutes. Now this could be is reasonable, but we don't know what their desert is. But 40 times is a lot of practice.

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What is 3/4. ÷ 1/6

spayn [35]

Answer:

3/4 ÷ 1/6 = 4 1/2

Step-by-step explanation:

wow that's a lot of points man.

just 4 this wow....

5 0

3 years ago

Read 2 more answers

Will give crown thingy 5 stars a thanks and 10 points to whoever helps me with this!!!!!!!

cupoosta [38]

Answer:29.15

Step-by-step explanation:

You just divide 21.20 by 8 then multiply

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3 years ago

Solve the given integral equation for LaTeX: y(t)y ( t ). LaTeX: y(t)+9\displaystyle{\int_{0}^{t}e^{9(t-v)}y(v)\, dv}=\sin(3t)y

choli [55]

Looks like the equation is

$y(t)+9\displaystyle\int_0^te^{9(t-v)}y(v)\,\mathrm dv=\sin(3t)$

Differentiating both sides yields the linear ODE,

$y'(t)+9e^{9(t-t)}y(t)=3\cos(3t)$

$y'(t)+9y(t)=3\cos(3t)$

Multiply both sides by the integrating factor $e^{9t}$ :

$e^{9t}y'(t)+9e^{9t}y(t)=3e^{9t}\cos(3t)$

$\left(e^{9t}y(t)\right)'=3e^{9t}\cos(3t)$

Integrate both sides, then solve for $y(t)$ :

$e^{9t}y(t)=\dfrac1{10}e^{9t}(\sin(3t)+3\cos(3t))+C$

$y(t)=\dfrac{\sin(3t)+3\cos(3t)}{10}+Ce^{-9t}$

The given answer choices all seem to be missing <em>C</em>, so I suspect you left out an initial condition. But we can find one; let $t=0$ , then the integral vanishes and we're left with $y(0)=0$ . So

$0=\dfrac{0+3}{10}+C\implies C=-\dfrac3{10}$

So the particular solution is

$y(t)=\dfrac{\sin(3t)+3\cos(3t)-3e^{-9t}}{10}$

6 0

2 years ago

Knowing that

Molodets [167]

Answer:

a. x/y = 2 b) y/x +y =1/3 c) x-y/y= 1 d) y/x = 1/2

Step-by-step explanation:

Solve for

a) x/y

as we know x +y/y = 3

x+y= 3y

x= 3y-y

x= y(3-1)

x/y= 3-1

x/y = 2

b) y/x+y

as we know x +y/y = 3

x+y = 3y

1= 3y/x+y

1/3 = y/x+y

So y/x +y =1/3

C) x-y /y

as we know x +y/y = 3

x +y = 3y

subtracting 2y from both sides

x +y -2y = 3y- 2y

x-y = y

dividing both sides by y

x-y/y = y/y

x-y/y= 1

d) y/x

as we know x +y/y = 3

x +y = 3y

x= 3y- y

x= 2y

dividing both sides by x

x/x = 2y/2x

1 = 2 x (y/x)

1 / 2 = y/x

Or y/x = 1/2

Best of luck.

please mark me brainliest.

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3 years ago

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Colt1911 [192]

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3 years ago