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3 years ago

What is the value of

Mathematics

1 answer:

LiRa [457]3 years ago

4 0

Answer:

Step-by-step explanation:

-8(17-12)

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

-2(8-(-2)

= -8(5)

--------

-2(10)

= -40

----------

-20

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Use the exponential decay model, Upper A equals Upper A 0 e Superscript kt, to solve the following. The half-life of a certai

Akimi4 [234]

Answer:

It will take 7 years ( approx )

Step-by-step explanation:

Given equation that shows the amount of the substance after t years,

$A=A_0 e^{kt}$

Where,

$A_0$ = Initial amount of the substance,

If the half life of the substance is 19 years,

Then if t = 19, amount of the substance = $\frac{A_0}{2}$ ,

i.e.

$\frac{A_0}{2}=A_0 e^{19k}$

$\frac{1}{2} = e^{19k}$

$0.5 = e^{19k}$

Taking ln both sides,

$\ln(0.5) = \ln(e^{19k})$

$\ln(0.5) = 19k$

$\implies k = \frac{\ln(0.5)}{19}\approx -0.03648$

Now, if the substance to decay to 78% of its original amount,

Then $A=78\% \text{ of }A_0 =\frac{78A_0}{100}=0.78 A_0$

$0.78 A_0=A_0 e^{-0.03648t}$

$0.78 = e^{-0.03648t}$

Again taking ln both sides,

$\ln(0.78) = -0.03648t$

$-0.24846=-0.03648t$

$\implies t = \frac{0.24846}{0.03648}=6.81085\approx 7$

Hence, approximately the substance would be 78% of its initial value after 7 years.

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3 years ago

Which postulate or theorem proves that △ RNM and △ QNP are congruent?

Zigmanuir [339]

SAS since ∠RNM is congruent ∠PNQ by vertical angles which will give you the angle you need for SAS.

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4 years ago

Read 2 more answers

In a sale, a shop reduces all its prices by 10%.

stepladder [879]

Answer:

The phone roughly cost 302 dollars

Step-by-step explanation:

10% of 432=43.2

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432-129.6=302.4

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2 years ago

$186.00=

bogdanovich [222]

2 ten dollar bills, 1 one dollar bill.

20*8= 160
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3 years ago

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BartSMP [9]

Answer:

90 degrees

Step-by-step explanation:

since angle A's exterior angle is 90 on a straight line then angle a is 90. 180-90=90 for the rest

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3 years ago