The half life of a substance is 30 days. If there are 4.5 grams to start with, how much will be left after 23 days? Round to the nearest tenth of a gram. Be sure to label your answer.

Answers

Answer 1

65.4Step-by-step explanation:KHAN

Answer 2

Important formula:

[tex]N_t = N_0 (1/2)^\frac{t}{t_{1/2}}[/tex]

Here, you are trying to find Nt and you have N0 = 4.5g, t = 23 days, t1/2 = 30 days. Plug the values in and you should get 2.7g left after 23 days.


Related Questions

GH bisects LM at K. LK = 5x+2 and LM = 64 Find x

Answers

Answer:

x = 6

Step-by-step explanation:

Since GH bisects LM at K , then

LK = [tex]\frac{1}{2}[/tex] LM , that is

5x + 2 = [tex]\frac{1}{2}[/tex] × 64 = 32 ( subtract 2 from both sides )

5x = 30 ( divide both sides by 5 )

x = 6

The value of x is 6.

Here,

GH bisects LM at K.

LK = 5x+2 and LM = 64

We have to find the value of x.

What is Bisection in line?

Bisecting a line is cutting a line exactly in half. It may also be referred to as constructing a perpendicular bisector as the line you are drawing will be at a right angle to the original line.

Now,

GH bisects LM at K.

LK + KM = LM

2 LK = LM

2 ( 5x + 2 ) = 64

5x + 2 = 32

5x = 30

x = 6

Hence, The value of x is 6.

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i need help asap im timed

Answers

Answer:-

Refer to attachment for the required solution.

Answer:

Step-by-step explanation:

rewrite without parentheses and simplify (y-5)^2

Answers

Answer:

y^2 - 10y + 25

Step-by-step explanation:

(y - 5)^2 =

(y - 5) • (y - 5)

Multiply y times y

y^2

Add 5 and 5

10

Multiply 5 and 5

25

Add these terms together

y^2 - 10y + 25

Answer: (y - 5)² = y² - 10y + 25

Concept:

There are in total three general types of parentheses-squared method:

(a - b)² = a² - 2ab + b²(a + b)² = a² +2ab + b²(a - b) (a + b) = a² - b²

Solve:

Given = (y - 5)²

Apparently, the given expression accords with (a - b)², where [y] = [a] and [5] = [b].

(a - b)² = a² - 2ab + b²

(y - 5)² = y² - 2(y)(5) + 5² = y² - 10y + 25

Hope this helps!! :)

Please let me know if you have any questions

Pls help. I really suck at math.

Determine whether the following polygons are similar.

Answers

Answer:

They are not similar.

To easily check if they are similar, you only need to look at the degrees angles, since if the angles are the same, the lengths of the sides will always come out to be similar somehow.

Those triangles possess right angles as you can see the little square thingie in the corners.

Those are 90 degrees, and you can add the 30 degrees in the left shape to 90 to get 120.

There are 180 degrees in a triangle, so 180 - 120 = 60.

Therefore, the unknown angle is 60.

A 30 60 90 triangle is called a special right triangle since there are many useful ratios hidden inside.

The other triangle has a 55 degree angle which is not on the first, so they must not be similar.

Pls brainly dont delete this link, its useful.

https://blog.prepscholar.com/30-60-90-triangle-ratio-formula

This helps you understand the special triangles.

You don't suck at math, you suck at geometry imo, though only in this unit of geometry, probably good at others.

Step-by-step explanation:

Consider function f. (-412 + 6.3 + 36, 1 < -2 15, 2 < I 4 Are the statements about the graph of function ftrue or false? true false 2 false The graph crosses the y-axis at (0.–15). The graph has a point of discontinuity at I = The graph is increasing over the interval (4, co) The graph is decreasing over the interval (-12, -2). false The domain of the function is all real numbers. false​

Please help

Answers

Answer:

Behold.

Step-by-step explanation

The answer to the statement is 1)false 2) false 3) true 4) true and 5) false.

Given functions,f

1) For x ≤ -2: f(x) = -12 + 6x

2) For -2 < x < 1: f(x) = 41 - 15x

3) For x ≥ 1: f(x) = 31 - 4x

1) The graph crosses the y-axis at (0, -15).

This is false because if x = 0, the function value would be -12 + 6 * 0 = -12, not -15.

2) The graph has a point of discontinuity at x = 1.

This is false because the function is defined at x = 1 there is no space, so there is no point of discontinuity at x = 1.

3) The graph is increasing over the interval (4, ∞).

This is true because the coefficient of x in the function's expression is negative, showing that it is decreasing. Therefore, as x increases, the function values decrease.

4) The graph is decreasing over the interval (-12, -2).

This is true because the coefficient of x in the first piece of the function (-12 + 6x) is positive, showing an increasing trend. Therefore, as x decreases from -12 to -2, the function values increase.

Statement 5: The domain of the function is all real numbers.

This is false because the domain of the function is limited by the intervals in its definition. The function is defined differently for different intervals of x.

So, the answer to the statement is

1) false

2) false

3) true

4) true

5) false

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Plzz help me with this question my class test is going on​

Answers

Step-by-step explanation:

2x+3y+5+4x-7y-8

2x+4x+3y-7y+5-8

6x-4y-3

Answer:

6x - 4y - 3

Step-by-step explanation:

They are basically telling you to sum both equations. So,

(2x + 3y + 5) + (4x - 7y - 8)

= 2x + 4x + 3y - 7y + 5 - 8

= 6x - 4y - 3

Anyone wanna help with this please ?

Answers

Answer:

y = mx + b

m = slope = -2

To find the y-intercept(b), substitute the points into the function:

-3 = -2(-5)  + b

-3 = 10 + b

b = -3 - 10 = -13

Therefore, y = -2x - 13

Answer:

Step-by-step explanation:

In algebraic expression


The sum of a number and six, divided by eight.

Answers

Answer:

x + 6 / 8

Step-by-step explanation:

The sum of a number is the answer to addition. So that means an unknown number and 6 are being added together. Lets make this unknown number x.

x + 6

The sum of this is being divided by 8. Since we already know what division is, we can just add the line and 8.

x + 6 / 8

Tutorial
Emmy already owns 22 hair bands, and additional hair bands are priced at 1 for a dollar.
How much money does Emmy need to spend on new hair bands in order to own a total of
38 hair bands?

Answers

Answer:

16

Step-by-step explanation:

38-22=16

Instructions: Find the value of the trigonometric ratio. Make sure to
simplify the fraction if needed.
С
32
40
B
24
A
Tan C =

Answers

Answer:

tanC will be given by the opposite over the adjacent

tanC=24/32

simplified to 6/8

I hope this helps

what is the result of converting 1260

Answers

Answer:

hiyupbhhhhkigkzblbbbgedvflr

rachel rides her bicycle due east at 9 miles per hour amos rides his bicycle due north at 12 miles per hour if they left from the same point at the same time how far apart will they be after 1 hour

Answers

The distance between Rachel and Amos after one hour is 15 miles.

What is an equation?

An equation is an expression that shows the relationship between two or more numbers and variables.

Distance travelled by Rachel after one hour = 9 mph * 1 h = 9 miles

Distance travelled by Amos after one hour = 12 mph * 1 h = 12 miles

Let x represent the distance between Rachel and Amos, hence:

x² = 9² + 12²

x = 15

The distance between Rachel and Amos after one hour is 15 miles.

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Using the Pythagorean Theorem, they will be 15 miles apart after one hour.

What is the Pythagorean Theorem?

The Pythagorean Theorem relates the length of the legs [tex]l_1[/tex] and [tex]l_2[/tex] of a right triangle with the length of the hypotenuse h, according to the following equation:

[tex]h^2 = l_1^2 + l_2^2[/tex]

For this problem, considering their directions, their distance is the hypotenuse of a right triangle of legs 9 miles and 12 miles, hence:

[tex]d^2 = 9^2 + 12^2[/tex]

[tex]d = \sqrt{9^2 + 12^2}[/tex]

d = 15 miles

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can you help me please.

Answers

Answer:

-86

Step-by-step explanation:

-102-

98 so the answer is -86

Help pls, I need Help :D

Answers

Answer:

5

Step-by-step explanation:

Step 1. Get two points off the graph

Points: (-70, 0) and (-60, 50)

Step 2. Use the two points to find the slope

m = slope

m = change in y/change in x

m = y2 - y1/x2 - x1

m = 50 - 0/-60 - -70

m = 50/10

m = 5/1

m = 5

The slope is 5

7(8+a)=189 please help and give me step by step ​

Answers

Answer: a = 19

Step-by-step explanation:

Given

7 (8 + a) = 189

Divide 7 on both sides

7 (8 + a) / 7 = 189 / 7

8 + a = 27

Subtract 8 on both sides

8 + a - 8 = 27 - 8

a = 19

Hope this helps!! :)

Please let me know if you have any questions

Well, we can use the distributive property:
56 + 7a = 189
7a = 133
a = 19

Find the principal amount invested if there is $9300 in the account after 5 years and earned 4% simple interest per year.

Answers

Answer:

11314.87379 (This is still rounded).

Step-by-step explanation:

Year 1:

9300*4%=372. 9300+372=9672.

Year 2:

9672*4%=386.88. 386.88=10058.88.

Year 3:

10058.88*4%=402.3552. 402.3552+10058.88=10461.2352.

Year 4:

10461.2352*4%=418.449408. 418.449408+10461.2352=10879.68461

Year 5:

10879.68461*4%=435.1873843. 435.1873843+10879.68461=11314.87379.

If y = 3x +1 were changed to y = x+1, how would the graph of the new function
compare with the original?
A. It would be shifted down.
B. It would be shifted up.
C. It would be less steep.
D. It would be steeper.

Answers

Answer:

Step-by-step explanation:

The standard form of a linear equation, a line, is y = mx + b, where m is the slope. The rule is the higher this value of m, the steeper the graph is. If we have the original equation y = 3x + 1, its slope m is 3; in the "new" equation, y = x + 1, its slope is 1. So the "new" equation would be less steep because the slope is a lower value than the original.

PLEASE HELP! I'LL GIVE BRAINLIEST:)

The center of the circle whose equation is (x + 2)² + (y - 3)² = 25 is (2, -3) (2, 3) (-2, 3)

Answers

Step-by-step explanation:

We know that if (h,k) is the center of any circle and whose radius is = r then its equation is :

[tex] {(x - h)}^{2} + {(y - k)}^{2} = {r}^{2} [/tex]

Given, the equation of circle

[tex] {(x + 2)}^{2} + (y - 3) ^{2} = 25 = {5}^{2} [/tex]

By comparing, we will get,

h = -2

k = 3

So, center of the circle is ( -2,3)

[tex]\large \green{ \: \: \: \: \boxed{\boxed{\begin{array}{cc} \bf\:Mark\\\bf\:me\:as\\\bf brainliest \end{array}}}} \\ [/tex]

Answer:

-2;3

Step-by-step explanation:

we have a formular

(x-a)^2 +(y-b)^2=c

the center of the cirlce is (a;b)

so in this case it's (-2;3)

Geometry, please answer question ASAP

Answers

Answer:

It's 5 which is A.

Step-by-step explanation:

If x-2y=6 and x+y=10.Find 2x+2y.

Answers

Answer:

20

Step-by-step explanation:

x-2y=6 and x+y=10

Multiply the second equation by 2

2x+2y = 20

Pleeeeeeeeaaaaaaaaaaaasse help 71 points!!!!!!!!!

Answers

Answer:

54

Step-by-step explanation:

The perimeter is the sum of the outside

P = 8+4+5+10+( 4+10) +(8+5)

P = 54

The weekly earnings of students in one age group are normally distributed with a standard deviation of 88 dollars. A researcher wishes to estimate the mean weekly earnings of students in this age group. Find the sample size needed to assure with 98 percent confidence that the sample mean will not differ from the population mean by more than 2 dollars.

Answers

Answer:

The sample size needed is of 10,484.

Step-by-step explanation:

We have to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.98}{2} = 0.01[/tex]

Now, we have to find z in the Z-table as such z has a p-value of [tex]1 - \alpha[/tex].

That is z with a p-value of [tex]1 - 0.01 = 0.99[/tex], so Z = 2.327.

Now, find the margin of error M as such

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.

The weekly earnings of students in one age group are normally distributed with a standard deviation of 88 dollars.

This means that [tex]\sigma = 88[/tex]

Find the sample size needed to assure with 98 percent confidence that the sample mean will not differ from the population mean by more than 2 dollars.

This is n for which M = 2. So

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]2 = 2.327\frac{88}{\sqrt{n}}[/tex]

[tex]2\sqrt{n} = 2.327*88[/tex]

[tex]\sqrt{n} = \frac{2.327*88}{2}[/tex]

[tex](\sqrt{n})^2 = (\frac{2.327*88}{2})^2[/tex]

[tex]n = 10483.3[/tex]

Rounding up:

The sample size needed is of 10,484.

The Master Chief collects spiders and starfish. If his spiders have 8 legs and his starfish have 5 legs, how many starfish must he have, given that his spider/starfish collection totals 19 creatures and 116 legs

Answers

Answer:

12 starfish

Step-by-step explanation:

Create a system of equations where x is the number of starfish he has and y is the number of spiders he has:

x + y = 19

5x + 8y = 116

Solve by elimination by multiplying the top equation by -8:

-8x - 8y = -152

5x + 8y = 116

Add these together and solve for x:

-3x = -36

x = 12

So, he has 12 starfish.

The total number of starfish is 12 starfishes

What is an Equation?

Equations are mathematical statements with two algebraic expressions flanking the equals (=) sign on either side.

It demonstrates the equality of the relationship between the expressions printed on the left and right sides.

Coefficients, variables, operators, constants, terms, expressions, and the equal to sign are some of the components of an equation. The "=" sign and terms on both sides must always be present when writing an equation.

Given data ,

Let the number of starfish be = x

Let the number of spiders be = y

The number of legs for spiders = 8

The number of legs for starfish = 5

So , the equation will be

The total number of legs for x starfish = 5x

The total number of legs for y spiders = 8y

The total number of creatures = 19

So , x + y = 19   be equation (1)

And ,

The total number of legs = 116

So , 5x + 8y = 116   be equation (2)

Now , from equation (1) , x = 19 - y

Substituting the value of equation (1) in equation (2) , we get

5x + 8y = 116

5 ( 19 - y ) + 8y = 116

95 - 5y + 8y = 116

95 + 3y = 116

Subtracting 95 on both sides , we get

3y = 21

Divide by 3 on both sides , we get

y = 7

So , the number of spiders is 7 spiders

Substituting the value of y in equation (1) , we get

x + y = 19

x + 7 = 19

Subtract 7 on both sides , we get

x = 12

Therefore , the value of x is 12

Hence , The total number of starfish is 12 starfishes

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how do i solve n pls help

Answers

Answer:

Improper Fraction-n=96/5     Mixed Number-n=19 1/5

Step-by-step explanation:

Answer:

n = [tex]\frac{96}{5}[/tex]

Step-by-step explanation:

Given

[tex]\frac{12}{5}[/tex] = [tex]\frac{n}{8}[/tex] ( cross- multiply )

5n = 96 ( divide both sides by 5 )

n = [tex]\frac{96}{5}[/tex]

A shop owner made a loss of 12% when he sold an item for $264. What was the cost price of the item?.​

Answers

Answer:

The cost of the item was $31.68

Step-by-step explanation:

Things to understand for this type of question!

• Converting

• Percentage

————————————————————

We are trying to find out 12% or $264

Step 1. Use part/whole = part/whole

12% is part of $264 in total

12%/100% = ?/$264

Step 2. Multiply $264 by 12% and divided by 100

12%/100% = $31.68/$264
••••••••••••••••••••••••••••••••••••••••••••••••••
Therefore, the shop owner loss $31.68

Find the missing angle. Round your answer to the nearest tenth. PLS HURRY.

Answers

Answer:

x = 24.4°

Hope this helps... Have a good day!!

I need help to find n =

Answers

Answer:

n = √108

Step-by-step explanation:

Use similar triangles or the right triangle altitude theorem.

18/n = n/6

n^2 = 18 * 6

n^2 = 108

n = √108

Someone plz help me on this

Answers

Answer:

9²+x²=13²

81+x²=169

x²= 169-81

x²=88

X= 9.38

x=9.4

[tex]x = \sqrt{88} [/tex]

Geometry - Triangle d) In the given figure, BE = EC and CE is the bisector of ZACB. Prove that ZBEC = ZACD. E B D С​

Answers

Answer:

Let m∠BCE = x

Then m∠ACE = x as well since CE is bisecting ∠ACB.

m∠ACD + x + x = 180° ⇒ m∠ACD = 180° - 2x

Consider ΔBEC

Since BE = EC, the opposite angles are congruent:

∠BCE ≅ ∠CBE

Then:

m∠CBE = m∠BCE = x

Find the angle BEC:

m∠BEC = 180° - (x + x) = 180° - 2x

Comparing the above we see that:

m∠BEC = m∠ACDproved

Write down all the prime numbers between 20 and 70

Answers

Answer:

23,29,31,37,41,43,47,53,59,61 and 67.

Step-by-step explanation:

If you like my answer than please mark me brainliest thanks

Answer:

23, 29, 31, 37, 41, 43, 47, 53, 61, 67

Step-by-step explanation:

Im not entirely sure but I believe I'm correct here.

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