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2 years ago

URGENT HELP ASAP, PLEASE HELP WITH MY GRADE 11 MATH!

Mathematics

1 answer:

cluponka [151]2 years ago

4 0

Half-Life Formula:

Amount remaining = (Initial amount)[ (1/2)^(time / half-life) ]

Amount remaining = ?

Initial amount = 200 mg

Time = 2 hours = 120 minutes

Half-Life = 20 mins

---Notice that I changed the time from hours to minutes. The time and half-life time need to be in the same unit.

A = (200)[ (1/2)^(120/20) ]

A = (200)(1/2 ^6)

A = (200)(1/64)

A = 3.125

Answer: 3.125 mg remain

Hope this helps!

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Helppppp can someone answer these questions please

Delvig [45]

Answer:

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Step-by-step explanation:

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3 years ago

What phrases describes the expression of 16-y

Jlenok [28]

What phrases describes the expression of 16-y

Answer: -9

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3 years ago

1) Use power series to find the series solution to the differential equation y'+2y = 0 PLEASE SHOW ALL YOUR WORK, OR RISK LOSING

iogann1982 [59]

$y=\displaystyle\sum_{n=0}^\infty a_nx^n$

then

$y'=\displaystyle\sum_{n=1}^\infty na_nx^{n-1}=\sum_{n=0}^\infty(n+1)a_{n+1}x^n$

The ODE in terms of these series is

$\displaystyle\sum_{n=0}^\infty(n+1)a_{n+1}x^n+2\sum_{n=0}^\infty a_nx^n=0$

$\displaystyle\sum_{n=0}^\infty\bigg(a_{n+1}+2a_n\bigg)x^n=0$

$\implies\begin{cases}a_0=y(0)\\(n+1)a_{n+1}=-2a_n&\text{for }n\ge0\end{cases}$

We can solve the recurrence exactly by substitution:

$a_{n+1}=-\dfrac2{n+1}a_n=\dfrac{2^2}{(n+1)n}a_{n-1}=-\dfrac{2^3}{(n+1)n(n-1)}a_{n-2}=\cdots=\dfrac{(-2)^{n+1}}{(n+1)!}a_0$

$\implies a_n=\dfrac{(-2)^n}{n!}a_0$

So the ODE has solution

$y(x)=\displaystyle a_0\sum_{n=0}^\infty\frac{(-2x)^n}{n!}$

which you may recognize as the power series of the exponential function. Then

$\boxed{y(x)=a_0e^{-2x}}$

7 0

3 years ago

What is the solution to the equation

Firdavs [7]

3c/5-1/2=-31/2 Add 1/2 both sides
+1/2 +1/2
3c/5=-30/2 Then simplify the fraction
(5)3c/5=-15(5) Multiply 5 both sides
3c=75 Finally, divide by 3 both sides
c=25
So the answer to your question is E.

7 0

3 years ago

What is the value of the x variable in the solution to the following system of equations?

defon

ANSWER

The correct answer is C $x=3$ .

EXPLANATION

We have

$4x+2y=12---(1)$

and

$x-y=3---(2)$ .

We solve the two equation simultaneously by elimination method. We need to be smart and eliminate y, since we are looking for $x$ .

We first multiply equation (2) by 2

$2x-2y=6---(3)$ .

We add equation (3) and (1).

$\Rightarrow 6x=18$ .

Dividing through by 6 gives

$x=3$ .

7 0

3 years ago