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BabaBlast [244]

1 year ago

12

The width of a rectangle measures (2h-6) centimeters, and its length measures (7h+8) centimeters. Which expression represents th

e perimeter, in centimeters, of the rectangle?

1 answer:

dedylja [7]1 year ago

4 0

Answer:

18h +4

Step-by-step explanation:

The perimeter of a rectangle is given by

P = 2(l+w) where l is the length and w is the width

=2( 7h+8 + 2h-6)

Combine like terms

= 2( 9h+2)

Distribute

= 18h +4

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If d=8, find the value of 3d. _____

yan [13]

Answer:

24

Step-by-step explanation:

3d

= 3 × 8

= 24

Hope it helps you:)

3 0

1 year ago

Read 2 more answers

Need help with my math!

kykrilka [37]

12x+7+6x-7=90
12x+6x=90
18x=90
x=5

6(5)-7=
30-7=23

Q=23

7 0

2 years ago

A tank contains 180 gallons of water and 15 oz of salt. water containing a salt concentration of 17(1+15sint) oz/gal flows into

Stels [109]

Let A(t) denote the amount of salt (in ounces, oz) in the tank at time t (in minutes, min).

Salt flows in at a rate of

$\dfrac{dA}{dt}_{\rm in} = \left(17 (1 + 15 \sin(t)) \dfrac{\rm oz}{\rm gal}\right) \left(8\dfrac{\rm gal}{\rm min}\right) = 136 (1 + 15 \sin(t)) \dfrac{\rm oz}{\min}$

and flows out at a rate of

$\dfrac{dA}{dt}_{\rm out} = \left(\dfrac{A(t) \, \mathrm{oz}}{180 \,\mathrm{gal} + \left(8\frac{\rm gal}{\rm min} - 8\frac{\rm gal}{\rm min}\right) (t \, \mathrm{min})}\right) \left(8 \dfrac{\rm gal}{\rm min}\right) = \dfrac{A(t)}{180} \dfrac{\rm oz}{\rm min}$

so that the net rate of change in the amount of salt in the tank is given by the linear differential equation

$\dfrac{dA}{dt} = \dfrac{dA}{dt}_{\rm in} - \dfrac{dA}{dt}_{\rm out} \iff \dfrac{dA}{dt} + \dfrac{A(t)}{180} = 136 (1 + 15 \sin(t))$

Multiply both sides by the integrating factor, $e^{t/180}$ , and rewrite the left side as the derivative of a product.

$e^{t/180} \dfrac{dA}{dt} + e^{t/180} \dfrac{A(t)}{180} = 136 e^{t/180} (1 + 15 \sin(t))$

$\dfrac d{dt}\left[e^{t/180} A(t)\right] = 136 e^{t/180} (1 + 15 \sin(t))$

Integrate both sides with respect to t (integrate the right side by parts):

$\displaystyle \int \frac d{dt}\left[e^{t/180} A(t)\right] \, dt = 136 \int e^{t/180} (1 + 15 \sin(t)) \, dt$

$\displaystyle e^{t/180} A(t) = \left(24,480 - \frac{66,096,000}{32,401} \cos(t) + \frac{367,200}{32,401} \sin(t)\right) e^{t/180} + C$

Solve for A(t) :

$\displaystyle A(t) = 24,480 - \frac{66,096,000}{32,401} \cos(t) + \frac{367,200}{32,401} \sin(t) + C e^{-t/180}$

The tank starts with A(0) = 15 oz of salt; use this to solve for the constant C.

$\displaystyle 15 = 24,480 - \frac{66,096,000}{32,401} + C \implies C = -\dfrac{726,594,465}{32,401}$

So,

$\displaystyle A(t) = 24,480 - \frac{66,096,000}{32,401} \cos(t) + \frac{367,200}{32,401} \sin(t) - \frac{726,594,465}{32,401} e^{-t/180}$

Recall the angle-sum identity for cosine:

$R \cos(x-\theta) = R \cos(\theta) \cos(x) + R \sin(\theta) \sin(x)$

so that we can condense the trigonometric terms in A(t). Solve for R and θ :

$R \cos(\theta) = -\dfrac{66,096,000}{32,401}$

$R \sin(\theta) = \dfrac{367,200}{32,401}$

Recall the Pythagorean identity and definition of tangent,

$\cos^2(x) + \sin^2(x) = 1$

$\tan(x) = \dfrac{\sin(x)}{\cos(x)}$

Then

$R^2 \cos^2(\theta) + R^2 \sin^2(\theta) = R^2 = \dfrac{134,835,840,000}{32,401} \implies R = \dfrac{367,200}{\sqrt{32,401}}$

and

$\dfrac{R \sin(\theta)}{R \cos(\theta)} = \tan(\theta) = -\dfrac{367,200}{66,096,000} = -\dfrac1{180} \\\\ \implies \theta = -\tan^{-1}\left(\dfrac1{180}\right) = -\cot^{-1}(180)$

so we can rewrite A(t) as

$\displaystyle A(t) = 24,480 + \frac{367,200}{\sqrt{32,401}} \cos\left(t + \cot^{-1}(180)\right) - \frac{726,594,465}{32,401} e^{-t/180}$

As t goes to infinity, the exponential term will converge to zero. Meanwhile the cosine term will oscillate between -1 and 1, so that A(t) will oscillate about the constant level of 24,480 oz between the extreme values of

$24,480 - \dfrac{267,200}{\sqrt{32,401}} \approx 22,995.6 \,\mathrm{oz}$

and

$24,480 + \dfrac{267,200}{\sqrt{32,401}} \approx 25,964.4 \,\mathrm{oz}$

which is to say, with amplitude

$2 \times \dfrac{267,200}{\sqrt{32,401}} \approx \mathbf{2,968.84 \,oz}$

6 0

1 year ago

A customer placed an order with a bakery for cupcakes. The baker has completed 37.5% of the order 81 cupcakes. How many cupcakes

Paul [167]

Answer:

The total number of cupcakes ordered=216

Step-by-step explanation:

The total number of cupcakes ordered that the baker completed can be expressed as;

C=P×t

where;

C=Total number of completed order of cupcakes

P=percentage of order completed

t=total number of ordered cupcakes

In our case;

C=81

P=37.5%

t=t

replacing in the above expression;

81=37.5%×t

(37.5/100)×t=81

t=81×100/37.5

t=216

The total number of cupcakes ordered=216

3 0

2 years ago

HELP NEEDED ASAP WILL GIVE BRAINLIEST!!!!!!!!!!!!!!!!!!!

SCORPION-xisa [38]

Answer: (- $\infty$ , $\infty$ )

Step-by-step explanation:

The following graph is a graph with a slant asymptote, which is an asymptote that isn't horizontal or vertical (i.e. doesn't have a slope of 0 or $\infty$ ).

To review, an asymptote is a line that the graph of a function <u>approaches, but will never touch</u>. Normally, a horizontal asymptote would <u>limit the range</u> as the graph can never cross a certain y-value.

However, there is no such y-value that must not be crossed in a slant asymptote; therefore, there is not limitation to the range. The range would be all real numbers.

Hence, the range of function h is (- $\infty$ , $\infty$ ).

4 0

1 year ago