Solve by substitution or elimination

Step-by-step walkthrough:

a.

Well a standard half-life equation looks like this.

[tex]N = N_0 * (\frac{1}{2})^{t/p[/tex]

[tex]N_0[/tex] is the starting amount of parent element.

[tex]N[/tex] is the end amount of parent element

[tex]t[/tex] is the time elapsed

[tex]p[/tex] is a half-life decay period

We know that the starting amount is 74g, and the period for a half-life is 2.8 days.

Therefore you can create a function based off of the original equation, just sub in the values you already know.

[tex]N(t) = 74g * (\frac{1}{2})^{t/2.8days[/tex]

b.

This is easy now that we have already made the function. Here we just reuse it, but plug in 2.8 days.

[tex]N(t) = 74g * (\frac{1}{2})^{t/2.8days} = N(2.8days) = 74g * (\frac{1}{2})^{2.8days/2.8days}\\= 74g * \frac{1}{2} = 37g[/tex]

c.

Now we just gotta do some algebra. Use the original function but this time, replace [tex]N(t)[/tex] with 10g and solve algebraically.

[tex]10g = 74g * (\frac{1}{2})^{t/2.8days}\\\\\frac{10g}{74g} = (\frac{1}{2})^{t/2.8days}[/tex]

Take the log of both sides.

[tex]log(\frac{5}{37}) = log((\frac{1}{2})^{t/2.8days})[/tex]

Use the exponent rule for log laws that, [tex]log(b^x) = x*log(b)[/tex]

[tex]log(\frac{5}{37}) = \frac{t}{2.8days} * log(\frac{1}{2})[/tex]

[tex]\frac{log(\frac{5}{37})}{log(\frac{1}{2})} = \frac{t}{2.8days}[/tex]

[tex]2.8 * \frac{log(\frac{5}{37})}{log(\frac{1}{2})} = t[/tex]

slap that in your calculator and you get

[tex]t = 8.1 days[/tex]

Answer:

Your answer is C.

239-92

Step-by-step explanation:

If shes giving AWAY then it would be a subtraction problem.

Answer:

Adult Ticket = $13.00, Children Ticket = $4.00

Step-by-step explanation:
13*4=52, 4*9=36, 52+36=88

13*7=91, 4*5=20, 91+20=111

Answer:

0.728 to nearest thousandth.

Step-by-step explanation:

3(3 squared2 -4)

= 9√2 - 12

= 0.728 to nearest thousandth.

Answer:

[tex]\frac{1}{3} - \frac{1}{9} = \frac{3}{9} - \frac{1}{9} = \frac{2}{9}[/tex]

The first one: 3

The second one: [tex]\frac{2}{9}[/tex]

Step-by-step explanation:

To find the common numerator, you can multiply by 3 on both the numerator and denominator.

Yes julia is correct the run of the scond similar triangle will be b2=25.

The similar triangle are those whose three sides or one angle or two sides or two angles one side are equal.

In the given:

Height of first triangle h=3

Base of first traingle =10

Height of second triangle =7.5

The base of second triangle b2 = ?

From the triangle similarity

[tex]\dfrac{h_1}{b_1}=\dfrac{h_2}{b_2}[/tex]

[tex]\dfrac{3}{10}=\dfrac{7.5}{b_2}[/tex]

[tex]b_2=\dfrac{7.5\times 10}{3}[/tex]

[tex]b_2=25[/tex]

Thus julia is correct the run of the scond similar triangle will be b2=25.

To know more about similar triangle follow

https://brainly.com/question/2644832

[tex]~~~~~~ \textit{Compound Interest Earned Amount} \\\\ A=P\left(1+\frac{r}{n}\right)^{nt} \quad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{original amount deposited}\dotfill &\pounds 2000\\ r=rate\to 3\%\to \frac{3}{100}\dotfill &0.03\\ n= \begin{array}{llll} \textit{times it compounds per year}\\ \textit{per year, thus once} \end{array}\dotfill &1\\ t=years\dotfill &2 \end{cases} \\\\\\ A=2000\left(1+\frac{0.03}{1}\right)^{1\cdot 2}\implies A=2000(1.03)^2\implies A=2121.8[/tex]

Answer:

2,121.8

Step-by-step explanation:

2000(1.03)^2

please rate and mark as brainlest.

Answer:

[tex]0.3 = \frac{3}{10}\\\\ 0.46 = \frac{23}{50} \\\\0.075 = \frac{3}{40}[/tex]

Step-by-step explanation:

To convert decimals to fractions, you look at the place of the last digit of the fraction (i.e. the digit that the farthest right from the decimal)

For 0.3, 3 is in the tenths place, so we end up with the fraction [tex]\frac{3}{10}[/tex]

For 0.46, 6 is in the hundreths place, so before simplifying we have [tex]\frac{46}{100}[/tex]

The GCF of 46 and 100 is 2 so we divide the fraction by [tex]\frac{2}{2}[/tex] to get [tex]\frac{46}{100}[/tex] ÷[tex]\frac{2}{2}[/tex] = [tex]\frac{23}{50}[/tex]

For 0.075, the 5 is in the thousandths place, so before simplifying we have [tex]\frac{75}{1000}[/tex]

The GCF of 75 and 1000 is 25 so we decide the fraction by [tex]\frac{25}{25}[/tex] to get [tex]\frac{75}{1000}[/tex] ÷[tex]\frac{25}{25}[/tex] = [tex]\frac{3}{40}[/tex]

Step-by-step explanation:

258

because there are 360 degrees in a circle. 360 - 102 = 258

Answer:

The first, second, and fourth questions.

Step-by-step explanation:

None of these result in an answer of 23, so I'm assuming that you meant 2/3.

"Two gallons of water are needed to fill 3 fish tanks of equal size. How many gallons of water are required for each tank?"

2 gallons divided between 3 tanks is 2 divided by 3, so 2/3.

"Three cats share 2 cans of tuna. How much of a can does each cat receive?"

2 cans divided between 3 cats - it's the same as the above problem, just with cats and tuna cans instead of tanks and gallons of water. Each cat gets 2/3 of a can.

"Two bags of bird seed are split among 5 parrots. What fraction of a bag does each parrot receive?"

2 bags divided between 5 parrots would be 2/5 of a bag for each parrot.

"Two apples are split among 3 people. How much of an apple does each person receive?"

Two apples split among 3 people - like the first 2 questions, this also equals 2/3.

"Three dogs each drink 2 cups of water. How many cups of water do the dogs drink in all?"

Three dogs EACH drink 2 cups of water means that the answer is 2*3=6 cups.

"Three cupcakes are divided among 2 children. How much of a cupcake does each child receive?"

Three cupcakes are split between 2 children - they will each get 3/2 of a cupcake, or 1 1/2.

Answer:

  49.2 square yards

Step-by-step explanation:

The surface area of a rectangular prism can be found using the formula.

  A = 2(LW +H(L +W)) . . . . where L, W, H are length, width, height

  A = 2(3×5 +1.2(3 +5)) = 2(15 +9.6) = 49.2 . . . . square yards

Answer:

circle a: 3.14x36= 113.04

circle b: 3.14 x 64 = 200.96

circle c: 3.14 x 121= 379.94

circle d : 3.14 x 81 = 254.34

Step-by-step explanation: circle a is 6cm, circle b is 8 cm, circle c is 11 cm and circle d is 9cm.

and (Area = π r²) example: circle a 6²=36 and π=3.14 so 3.14x36=113.04

Answer:

b

Step-by-step explanation:

Answer:

⅙

Step-by-step explanation:

it could be 6 and 1, 5 and 2, 4 and 3, 3 and 4, 2 and 5 or 1 and 6.

It is 2 fair dice, so all together, the probability is 36.

6/36 can be simplified to ⅙

Answer:

498. 498/6 = 83.

Step-by-step explanation:

Answer:

432 feet^2

Step-by-step explanation:

If we fill in the edges, it'll be 24x8, since 16+2 is 18, and 20+2(2) is 24. 24x18 is 432. Brainliest please.

Answer:

2

Step-by-step explanation:

One we student has 9 letters and another has 10 letters

Answer:

x = -7

Step-by-step explanation:

Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other. Do the opposite of PEMDAS.

PEMDAS is the order of operations, and stands for:

Parenthesis

Exponents (&Roots)

Multiplications

Divisions

Additions

Subtractions

~

First, add 6 to both sides of the equation:

-5x - 6 = 29

-5x - 6  (+6) = 29 (+6)

-5x = 29 + 6

-5x = 35

Next, divide -5 from both sides of the equation:
(-5x)/-5 = (35)/-5

x = 35/-5

x = -7

-7 is your answer for x.

~

Step-by-step explanation:

[tex] \hookrightarrow \sf y = kx [/tex]

[tex] \sf where \: k \: is \: constant[/tex]

[tex] \sf \: k = \frac{y}{x} [/tex]

[tex] \hookrightarrow \sf \: k = \frac{y}{5.5} [/tex]

Equation = [tex] \sf \: k = \frac{y}{5.5} [/tex]

Answer:

C. 15 cm

Step-by-step explanation:

The formula to find the area of a circle is: π × r²

But since we need to solve for the radius, we use the formula:

[tex]r = \sqrt{ \dfrac{ A }{ \pi } \phantom{\tiny{!}}}[/tex]

r = radius

A = area

π = 3.14

Now we substitute the information given in the text into the equation

[tex]r = \sqrt{ \dfrac{ A }{ \pi } \phantom{\tiny{!}}}[/tex]

Substitute values into the equation

[tex]r = \sqrt{ \dfrac{ 706.5 }{ 3.14 } \phantom{\tiny{!}}}[/tex]

Divide 706.5 by 3.14

[tex]r = \sqrt{ 225 }[/tex]

Take the square root of 225

[tex]r = {15 }[/tex]

So, the radius of the pie is 15 cm

Answer:

30,976

Step-by-step explanation:

=}.

[tex](11 {}^{3} \times 4 { }^{2} \binom{}{11 {}^{2} } ) {}^{2} [/tex]

=}.

[tex](11 \times 4 {}^{2} ) {}^{2} [/tex]

=}.

[tex]121 \times (4 {}^{2} ) {}^{2} [/tex]

=}.

[tex]121 \times 256[/tex]

=}. 30,976

Answer:

Answer given above

Step-by-step explanation:

11^2 * 4^4

Answer:

the annswer is 4155 because its in formal information

Step-by-step explanation:

the annswer is 4155 because its in formal information

Answer:

[tex]\boxed{\sf{4}}}[/tex]

Step-by-step explanation:

Use a slope form.

Slope:

[tex]\sf{\dfrac{y_2-y_1}{x_2-x_1}=\dfrac{rise}{run} }[/tex]

y₂ = (17)

y₁ = (1)

x₂ = (2)

x₁ = (-2)

Then, rewrite the problem.

Solve.

[tex]\sf{\dfrac{17-1}{2-(-2)}=\dfrac{16}{4}=\dfrac{16\div4}{4\div4}=\dfrac{4}{1}=\boxed{\sf{4} }[/tex]

Therefore, the slope is 4, which is our answer.

I hope this helps you! Let me know if my answer is wrong or not.

Answer:

937.5

Step-by-step explanation:

Given:

75% of 1250

Note:

Of = Multiply

Solve:

75% × 1250

= 937.5

~Lenvy~

Answer:

937.5

Step-by-step explanation:

We Know That 75% Is Same As 75

100

So, You Start By Dividing That, Or Making The Calculation Together, You Say

[tex] \frac{75}{100} \times \frac{1250}1[/tex]

[tex]0.75 \times 1250[/tex]

[tex] = 937.5[/tex]

Answer:

B: 3x + 7 - 7 = 16 - 7

Step-by-step explanation:

B: 3x + 7 - 7 = 16 - 7

Answer:

[tex]\boxed{\sf{B. \quad3x + 7 - 7 = 16 - 7}}[/tex]

[tex]\boxed{\sf{x=3}}[/tex]

Step-by-step explanation:

Isolate the term of x from one side of the equation.

First, subtract by 7 from both sides.

⇒ 3x+7-7=16-7

Solve.

⇒ 16-7=9

Rewrite the problem down.

⇒ 3x=9

Divide by 3 from both sides.

⇒ 3x/3=9/3

Solve.

Divide the numbers from left to right.

⇒ 9/3=3

⇒ x=3

I hope this helps you! Let me know if my answer is wrong or not.

The two angles form a straight line and need to equal 180 degrees

180 - 61 = 119

The missing angle is 119 degrees

Answer:

Below in bold.

Step-by-step explanation:

30 = 2 * 3 * 5

12 = 2 * 2 * 3

Note that 2 and 3 are common to both factors

so the HCF = 2*3 = 6.

Only one 2 and one 3 of the duplicates are included in the LCM:

so the LCM = 2 * 3 * 2 * 5 =  60

20 = 2 * 2 * 5

12 = 2 * 2 * 3

HCF = 2 *2 = 4

LCM = 2*2*3*5 = 60.