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swat32
3 years ago
5

A radioactive substance decays exponentially. A scientist begins with 190 milligrams of a radioactive

Mathematics
1 answer:
worty [1.4K]3 years ago
6 0

Answer: 65.1 (mg)

Step-by-step explanation:

y=190*e^{-a*t}\\\\Calculate\ a:\\\\t=33,y=95(mg)\\\\190*e^{-a*33}=95\\\\e^{-a*33}=0.5\\\\-a*33=ln(0.5)\\\\a=\dfrac{ln(\dfrac{1}{2}) }{-33} \\\\a=0,02100... \approx{0.021}\\\\If\ t=51\ h, y=190*e^{-0.02100*51}=65.09167...\approx{65.1}

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Bethany is baking cookies for her school's bake sale. She plans to bake more than 185 cookies, in batchs or 12 cookies. so far,
Aleks [24]

Answer:

48+12b≥185

Step-by-step explanation:

Inequality: 48+12b≥185

Why? she has already backed 48 cookies so you just need to find how many more she needs to bake. (she doesn't need 185 cookies anymore since she's already baked 48)

You don' t need to solve the question,  

But here is how you do...

12b≥137

b≥11.42 (roughly)

5 0
3 years ago
What is the radical form of the expression 432 ? PLEASE HELP!!!!!
oksano4ka [1.4K]

Answer:

12√3

Step-by-step explanation:

well first divide 432 by 3

that gives you 144

so you have 144×3

you then but them both in radicals

144 is a perfect square i.e 12×12=144

3 isnt

therefore the answer is 12√3

4 0
3 years ago
Select all the expressions that are equivalent to −5/6 / -1/3
Sindrei [870]

Step-by-step explanation:

We need to find an expression for \dfrac{\dfrac{-5}{6}}{\dfrac{-1}{3}}.

We can solve it as follows.

We know that,

\dfrac{\dfrac{a}{b}}{\dfrac{c}{d}}=\dfrac{a}{b}\times \dfrac{d}{c}

So,

\dfrac{\dfrac{-5}{6}}{\dfrac{-1}{3}}=\dfrac{-5}{6}\times -3\\\\=\dfrac{5}{2}

or

=2\dfrac{1}{2}

Hence, this is the required solution.

3 0
2 years ago
A vehicle purchased for $
Nataly [62]

Answer:

$10,870

Step-by-step explanation:

we can multiply the initial value (27500) by (1-.06), or 0.94, raised to the 15th power

27500(.94)^15 = 10,870.52

6 0
2 years ago
The sum of twelve and a number is no greater than the sum of twice the number and -8
krok68 [10]
The sum of 12 and a number
(12 + n)

is no greater
< = 

then the sum of twice the number and 8
(2n +(-8)) = (2n - 8)

so we have :
(12 + n) < = (2n - 8)
4 0
3 years ago
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