Element X is a radioactive isotope such that every 20 years, its mass
decreases by half. Given that the initial mass of a sample of Element X is 410
grams, how long would it be until the mass of the sample reached 270 grams,
to the nearest tenth of a year?

Answer:

n = -6

x = -7

n = 27

Step-by-step explanation:

Question 1

-3n - n + 12 = 36

First we get all the variables to one side using subtraction property of equality.

-3n - n + 12 (-12) = 36 (-12)

-4n = 24

divide by the coefficient of n to isolate the variable

-4n/-4 = 24/-4

n = -6

Question 2

-2x - 3x - 15 = 20

-5x - 15 = 20

-5x = 35

x = -7

Question 3

3 + n/9 = 6

Isolate the n variable

n/9 = 6 - 3

multiply by 9

n = 27

Answer:

1. n = -6

2. x = -7

3. n = 27

Answer:

A. E = 20H

B. $380

Step-by-step explanation:

E = 20(19) since she worked 19 hrs. This equals 380

Answer:y=-1/4x-2

Step-by-step explanation:

Answer:

y=-5x+30

Step-by-step explanation:

So negative 5x because you are taking five dollars out every x day so then plus 30 because since its slope intercept form y=mx+b and be is the y intercept then that should be your answer.

Answer:

the answer is c I believe

Step-by-step explanation:

5(10) 50 + 25 is 75 equals 25 and 10 + 5 is 15 so 75 + 15 is 90. so the answer is c

Answer:

Reflection

Step-by-step explanation:

You only flip the triangle it doesn't rotate or slide so its Reflection

Answer:

6.3

Step-by-step explanation:

7squared - 3squared

49-9= 40

square root of 40 = 6.3

Answer:

$0.05 per ounce

Step-by-step explanation:

Mrs. O'Brien purchases 112 ounces of laundry detergent for $13.44.

Units price = Total cost of the detergent / number of ounces

= $13.44 / 112 ounces

= $0.12 per ounce

Mr. O'Brien purchases a 280 ounce container of laundry detergent for $19.60.

Units price =Total cost of the detergent / number of ounces

= $19.60 / 280 ounces

= $0.07 per ounce

Difference in the unit price per ounce for the laundry detergents Mr. And Mrs. O'Brien purchase = $0.12 per ounce - $0.07 per ounce

= $0.05 per ounce

Answer:

Yes

Step-by-step explanation:

Because I can assist you hit my inbox

Answer:

help you with what?

Step-by-step explanation:

post the question and I am probably 90% sure I can answer it for you I just need to know what the question is . if you've already got it done then no need to answer back .

Answer:

8x

Step-by-step explanation:

Combine Like Terms:

= x+2x+5x

= (x+2x+5x)

= 8x

Answer:

213,645.6cm³

Step-by-step explanation:

Area of a cylinder is expressed as;

V = πr²h

r is the radius = 2cm

h is the height = 70cm

Get the volume of one rod;

V = πr²h

V = (3.14)(2)²(70)

V = (3.14)(4)(70)

V = 879.2cm³

one steel = 879.2cm³

243 rods = x

Cross multiply;

x = 879.2 * 243

x = 213,645.6

The company will need 213,645.6cm³ volume of steel to make 243 rods

Answer:

Step-by-step explanation:

175-20%= 35 off

175-35=140

140*8% tax= 11.20 tax

140+11.20= 151.20

151.20*18% tip= 27.216

151.20+27.22=178.42 total

Answer:

y=2x-1

Step-by-step explanation;

First step you have to do is get you desmos graphing calculator

input the equation- 1/2x+4 when you put it you get your line

from there you have to find one of the equations from the answer choices which one is parallel from there input your four answer choices on your graphing calculator then look which of the equations is parallel to the equation -1/2x+4 when you do that you get y=2x-1

Hope this helps :)

Answer:

Soda tax — Should people have to pay an extra tax on soda or junk food?

Your conversation should include the following:

A total of at least five entries for each side (10 entries total—two to three sentences each)

Accurate facts used to support both perspectives

At least two properly cited sources used for research

Step-by-step explanation:

Answer:

=2

Step-by-step explanation:

Answer:

w= 2

Step-by-step explanation:

3-2w+4w=7. We move all terms to the left: 3-2w+4w-(7)=0,  Then we add all the numbers together, and all the variables: 2w-4=0. After, we move all terms containing w to the left, all other terms to the right: 2w=4, w=4/2

w=2

Answer: 18.85 in.

Step-by-step explanation:

you take ^ divide it by 2 get three then you take three and multiple it by

pi r2

Answer:

He brought 34 cookies to the fundraiser.

Step-by-step explanation:

1.25x + 25 = 67.50

1.25x = 67.50 - 25

1.25x = 42.50

x = 42.50/1.25

x = 34

Answer:

34 cookies in total.

Step-by-step explanation:

Well if he is selling cookies for $1.25 each and has a starter of 25$, we can already mark off 25$ from $67.50. Now it's just simple division, so 42.50/1.25 is 34 cookies being sold.

Answer:

a

Step-by-step explanation: ya boi got at least a 90 in all classes

Answer:

D

Step-by-step explanation:

Answer:

$1875

Step-by-step explanation:

Money available with Dubois family = $5000

Money to be spent on gasoline and motel room = [tex]\frac{1}{4}[/tex] of the total amount

Therefore,

Money to be spent on gasoline and motel room = [tex]\frac{1}{4} \times 5000 = \$1250[/tex]

Remaining amount of money = Total amount - Money spent on gasoline and motel room  

Remaining amount of money = $5000 - $1250 = $3750

As per question statement:

Half of the remaining money is to be spent on meals.

i.e. Money to be spent on meals = [tex]\frac{1}{2}\times \$3750 = \bold{\$1875}[/tex]

Therefore, the answer is:

$1875

Answer:

Step-by-step explanation:

2(k-5)+3k=k+6k=

We move all terms to the left:

2(k-5)+3k-(k+6k)=0

We add all the numbers together, and all the variables

2(k-5)+3k-(+7k)=0

We add all the numbers together, and all the variables

3k+2(k-5)-(+7k)=0

We multiply parentheses

3k+2k-(+7k)-10=0

We get rid of parentheses

3k+2k-7k-10=0

We add all the numbers together, and all the variables

-2k-10=0

We move all terms containing k to the left, all other terms to the right

-2k=10

k=10/-2

k=-5

Answer:

Definition: Standard deviation is the measure of dispersion of a set of data from its mean. It measures the absolute variability of a distribution; the higher the dispersion or variability, the greater is the standard deviation and greater will be the magnitude of the deviation of the value from their mean.

Answer:

I'm on the same thing. If I'm being honest I have no idea what it is and I'm kinda freaking out bc my school stuff is due tomorrow.

Step-by-step explanation:

Answer:

160+65%=264

Step-by-step explanation:

i think

Answer:

264 inches

Step-by-step explanation:

160/ 0.65 = 104

104 + 160 = 264

Answer:

5

Step-by-step explanation: