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3 years ago

This needs a little working out. Just part A to simplify to find 21.

Mathematics

1 answer:

prisoha [69]3 years ago

6 0

Answer:

see explanation

Step-by-step explanation:

Since the pentagon has one line of symmetry. This will be a vertical line through C, thus

CD = BC = x + 1 and ED = AB = 2x + 3

Perimeter = AE + ED + DC + CB + BA

= 4x + 2x + 3 + x + 1 + x + 1 + 2x + 3 = 10x + 8

Perimeter is given as 21, thus

(b)

10x + 8 = 21 (subtract 8 from both sides )

10x = 13 ( divide both sides by 10 )

x = $\frac{13}{10}$ = 1.3

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Evaluate the expression 3x2t when t is 1

JulsSmile [24]

Hey there!

The answer to your question is 6.

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3 x 2(1)

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Hope this helps your assignment! Have a great day! Good luck!

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3 years ago

The concentration of dichlorodiphenyltrichloroethane (DDT - an infamous pesticide) in Lake Michigan has been declining exponenti

mojhsa [17]

Answer: A) $y=13e^{-0.1359t}$

B) H = 5.10

C) Yes

Step-by-step explanation: Exponential Decay function is a model that describes the reducing of an amount by a constant rate over time. Generally, it is written in the form: $y(t)=Ce^{rt}$

A) C is initial quantity, in this case, the initial concentration of DDT. To determine r, using the data given:

$y(t)=Ce^{rt}$

$2.22=13e^{13r}$

$e^{13r}=0.1708$

Using a natural logarithm property called power rule:

$13r=ln(0.1708)$

$r=\frac{ln(0.1708)}{13}$

$r=-0.1359$

The decay function for concentration of DDT through the years is $y(t)=13e^{-0.1359t}$

B) The value of H is calculated by $y=C(0.5)^{\frac{t}{H} }$

$2.22=13(0.5)^{\frac{13}{H} }$

$(0.5)^{\frac{13}{H} }=0.1708$

Again, using power rule for logarithm:

$\frac{13}{H} log(0.5)=log(0.1708)$

$\frac{13}{H} =\frac{log(0.1708)}{log(0.5)}$

$\frac{13}{H} =2.55$

H = 5.10

Constant H in the half-life formula is H=5.10

C) Using model $y(t)=13e^{-0.1359t}$ to determine concentration of DDT in 1995:

$y(24)=13e^{-0.1359.24}$

y(24) = 0.5

By 1995, the concentration of DDT is 0.5 ppm, so using this model is possible to reduce such amount and more of DDT.

8 0

3 years ago

Hal bought 5 pencils for $0.56 each.How much did he pay in total?

IceJOKER [234]

Answer:

2.80$

Step-by-step explanation:

56 times 5

6 0

3 years ago

What is the approximate volume of the cone? Use 3.14 for it.help please

Vesna [10]

Answer:

157.08, so it is the first opition

Step-by-step explanation

Volume of a cone is pie x the radius squared by 2 x the hieght divided by 3

pie x 5^2 x 6/3

pie x 25 x 2

157.08

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3 years ago

Please help me find the area of this figure.

GREYUIT [131]

You basically have a triangle and a rectangle. seperate the two at first, the rectangle's area is 32 since 8*4=32
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add 7.5 and 32 to get 39.5

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3 years ago