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2 years ago

The population of blackbirds in a park is counted every year.

Mathematics

2 answers:

user100 [1]2 years ago

5 0

Answer:

the original population was 425

Step-by-step explanation:

Snezhnost [94]2 years ago

5 0

Answer:

425

Step-by-step explanation:

Let the original population of blackbirds be x.

Original population decreases by New population

100 24 76

x 24 323

Now we can make an expression like this.

100 ⇒ 76

x ⇒ 323

And now let us use cross multiplication and solve for x.

Let us solve it now.

323 × 100 = 76x

32300 = 76x

425= x

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1.) Alexander jumped off a cliff into the ocean in Acapulco while on vacation. His height as a function of time could be modeled

Dmitrij [34]

So hmmm check the graph below

now.. to find the vertex of any quadratic

$\bf \textit{vertex of a parabola}\\ \quad \\

\begin{array}{lccclll}
h(t)=&-16t^2&+16t&+480\\
&\uparrow &\uparrow &\uparrow \\
&a&b&c
\end{array}\qquad 
\left(-\cfrac{{{ b}}}{2{{ a}}}\quad ,\quad {{ c}}-\cfrac{{{ b}}^2}{4{{ a}}}\right)$

so... how long did it take? well, it took $\bf -\cfrac{{{ b}}}{2{{ a}}}$

what was the highest point? well, it was $\bf {{ c}}-\cfrac{{{ b}}^2}{4{{ a}}}$

when did he hit the water? well, at y = 0
that is $h(t) = -16t^2 + 16t + 480 \implies 0 = -16t^2 + 16t + 480,$

solve for "t"

6 0

3 years ago

Need answer to this urgently

valentina_108 [34]

Answer:

x=3

Step-by-step explanation:

25+134+4x+9+180

4x+168+180

4x+12

x=3

5 0

2 years ago

The half-life of a certain tranquilizer in the bloodstream is 22 hours. How long will it take for the drug to decay to 90% of

nasty-shy [4]

Answer:

It will take approximately 3.34 hours for the drug to decay to 90% of the original dosage

Step-by-step explanation:

As suggested, we use the formula for exponential decay:

$A(t)=A_0\,e^{-k\,t}$

From the given information, the half life of the drug in blood id 22 hours, so that means that it takes that number of hours to go from the initial value $A_0$ , to a final value equal to $A_0/2$ . Using this information we can find the decay rate "k" by solving for this parameter in the formula, and using the natural log function to bring the exponent down:

$A(t)=A_0\,e^{-k\,t}\\\frac{A_0}{2} =A_0\,e^{-k\,*22}\\\frac{A_0}{A_0*2} =e^{-k\,*22}\\\frac{1}{2} =e^{-k\,*22}\\ln(\frac{1}{2})=-k\,*22\\ k=-\frac{ln(\frac{1}{2})}{22} \\k=0.0315$

Now we use this value for the decay rate "k" to calculate how long it would take to decay to 90% of the original dose;

$A(t)=A_0\,e^{-0.0315\,t}\\0.9*A_0} =A_0\,e^{-0.0315\,t}\\\frac{0.9*A_0}{A_0} =e^{-0.0315\,t}\\0.9 =e^{-0.0315\,t}\\ln(0.9)=-0.0315\,t\\ t=-\frac{ln(0.9)}{0.0315} \\t=3.3447\,hours$

7 0

3 years ago

I NEED HELP WITH THIS PROBLEM

coldgirl [10]

Answer:

3 1/2, 3

Step-by-step explanation:

Good luck!

3 0

3 years ago

Read 2 more answers

Find the product. Write your answer in scientific notation. (7 x 10^-2) (8 x 10^5) =

lakkis [162]

Answer:

7×10^(-2)×8×10^5 = 56000

convert to scientific notation = 5.6 × 10^4

(scientific notation)

= 5.6e4

(scientific e notation)

= 56 × 10^3

(engineering notation)

(thousand; prefix kilo- (k))

= 56000

(real number)

Step-by-step explanation:

6 0

2 years ago