How did the temperature change if: at first it's increased by 25% then decreased by 40%

Answer:

We can say we start with 490 grams and after 1 year we have (490 * .81 grams) or 396.9 grams.

We can solve for half-life by this equation:

Half life = (time * log 2) / log (beginning amount / ending amount)

Half-life = (1 year * 0.30102999566) / log (490 / 396.9)

Half life = (1 year * 0.30102999566) / log (1.2345679012 )

Half life = (0.30102999566) / 0.091514981109

Half-Life = 3.2894067399  years

Well, that's a start.

Step-by-step explanation:

The half life of the given radioactive isotope will be 3.2894067399  years.

The amount of time it takes to disintegrate by half an initial amount. For a given reaction, a reactant's half-life t-1/2 is the time it takes for its concentration to reach a value which is the arithmetic mean of its initial and final value.

Here, Element X starts with 490 grams

After 1 year we have  (490 X 0.81 grams) or 396.9 grams

Now, We can solve for half-life by this equation:

Half life = (time  X log 2) / log (beginning amount / ending amount)

Half-life = (1 year X 0.30102999566) / log (490 / 396.9)

Half life = (1 year X 0.30102999566) / log (1.2345679012 )

Half life = (0.30102999566) / 0.091514981109

Half-Life = 3.2894067399  years

Thus, the half life of the given radioactive isotope will be 3.2894067399  years.

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Answer:

20

Step-by-step explanation:

Solving  for x using the vertical angles we get , the value of x is: x = 20.

Here, we have,

from the given figure we get,

angle (2 + 3x) and angle62 are opposite angles.

we know that,

When two lines intersect each other, then the opposite angles, formed due to intersection are called vertical angles or vertically opposite angles. A pair of vertically opposite angles are always equal to each other.

so, we have,

angle (2 + 3x) = angle62

(2 + 3x) = 62

or, 3x = 60

or, x = 20

Hence, Solving  for x using the vertical angles we get , the value of x is: x = 20.

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Answer:

I think the answer is 42.

Step-by-step explanation:

If there is a 50% increase in members then the number of members would go up 14. Adding 14 to 28, you come away with 42.

Sorry if it's wrong.

Answer:

y = 1/2x + 4 1/2

Step-by-step explanation:

Answer:

One of the most basic concepts in statistics is hypothesis testing. Not just in Data Science, Hypothesis testing is important in every field. Want to know how??? Let us take an example. You must have heard about lifebuoy?? Suppose

lifebuoy claims that, it kills 99.9% of germs. So how can they say so? There has to be a testing technique to prove this claim right?? So hypothesis testing uses to prove a claim or any assumptions.

Hopefully, this helps! :D

Answer:

the answer is 114,210..................

Answer:

y= 1/2x-2

Step-by-step explanation:

Answer:

Slope= 4

Step-by-step explanation:

When you start at (0, 0) and then go to (1, 4), then you have to use the slope.

So, to figure out the slope, you have to do rise over run, rise/run.

So, as shown in the graph, the rise is 4 because the rise is the y so to get from 0 to 4, you have to add 4.

And the run, which would be the x side is 1 because to get from 0 to 1. You add 1.

This shows us that the slope is 4/1 which could be simplified to just 4.

Answer:

5x/7 - 3/7

Step-by-step explanation:

Answer:

thank you for the points :D

Step-by-step explanation:

Answer:

I don't know how to answer question 1, but the answer from question 2 is x=5

Step-by-step explanation:

The triangle shown is an isosceles triangle because it has two congruent sides. The base angles of isosceles triangles are congruent so ∠y=∠x. since the ∠x is 52 the ∠y is also 52. We subtract the measure of angles x and y in order to find the measure of the third angle. 180-(52+52) or 180-104 is 76. this means that 14x=6=76. All we have to do to get the answer now is solve. 76-6 is 70 and 70 divided by 14 is 5. x=5.

Answer:

[tex]6y^3z(8x^4yz^3-3)[/tex]

Step-by-step explanation:

Factor-[tex](-18y^3)(z)+48x^4y^4z^448x^4y^4z^4-18y^3z=6y^3z(8x^4yz^3-3)[/tex]

Answer:

(x+2) (x+1) (x-1)

Step-by-step explanation:

You would add and subtract the second term to the expression  

Factor x3+2x2−x−2

x3+2x2−x−2

=(x+2)(x+1)(x−1)

Answer:

15 years

Step-by-step explanation:

$40 x 15 (years) = 600

600 - 600 = 0

the person above me is right, it is a! good luck on your test <3

Answer:

You would have to multiple everything inside of the parenthesis by the number that's outside in this case it would be 2 ×7 and 2 × -9

Answer: 14n ,-18

Answer:

11 is one of the factors! The orange divisor(s) above are the prime factors of the number 990. If we put all of it together we have the factors 2 x 3 x 3 x 5 x 11 = 990.

Step-by-step explanation:

Answer:

2x2x3x5=11

Step-by-step explanation:

Answer:

The opposite sides of the rectangle are parallel.

Step-by-step explanation:

If that is true for all parallelograms and a rectangle is a parallelogram, then it should be true for a rectangle too, I think.

Answer:

The opposite sides of the rectangle are parallel. (for both questions)

Step-by-step explanation:

Got it right on edg

Dave's rate of completion is 4/3 walls per hour and this can be determined by using the concept of unit rate.

Given :

The following steps can be used in order to determine Dave's rate of completion:

Step 1 - The concept of unit rate can be used in order to determine Dave's rate of completion.

Step 2 - According to the given data, Dave completes on average 2/3 of a wall in 1/2 of an hour.

Step 3 - Now, let Dave's rate of completion be 'x'.

Step 4 - So, the value of 'x' can be calculated as:

[tex]x = \dfrac{\dfrac{2}{3}}{\dfrac{1}{2}}[/tex]

Step 5 - Simplify the above expression.

[tex]x = \dfrac{2}{3}\times\dfrac{2}{1}[/tex]

[tex]\rm x = \dfrac{4}{3}\;walls \;per \;hour[/tex]

Therefore, Dave's rate of completion is 4/3 walls per hour.

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Answer:

[tex]y = -2x + 10[/tex]

Step-by-step explanation:

Slope: [tex]m = \frac{y_{2}-y_{1} }{x_{2}-x_{1}}[/tex]

Slope-Intercept Form: [tex]y=mx+b[/tex]

[tex]m=\frac{8-0}{1-5}[/tex]

[tex]m = -2[/tex]

[tex]y = -2x + b[/tex]

[tex]0 = -2 (5)+b[/tex]

[tex]0=(-10)+b[/tex]

[tex]b = 10[/tex]

[tex]y = -2x + 10[/tex]

Answer:

Carter;

5 ( x + 9 ) - 3x = 2x + 45

Step-by-step explanation:

Simplify the equation;

5 ( x + 9 ) - 3x

Distribute the 5, remember, you have to distribute 5 over both terms.

5x + 45 - 3x

Combine like terms;

2x + 45

Answer: First Option (5√5)

Answer:

First, you see if there are any perfect squares that are a factor of 125. If you do find some, find what is seemingly the biggest. In this case, it is 25, I think. So you can then out it as root(25×5), I think. As 25 is a perfect square, you can square and then put the number you get on the outside. So since 5×5=25, it becomes 5(root)5, which essentially means 5×(root)5, I think.

Answer:

6552

Step-by-step explanation:

P.S Can I have brainliest?

Answer:

6,552

Step-by-step explanation:

Answer:

I think AB would be 67

BC would be 20 because its the whole line s 10+10 is 20

I am really sorry I don't know 1 and 4 I hope this helps tho

Also you dont have to give me brainliest

Step-by-step explanation:

Answer:

D<Q≤2 Or D<Q Q+D≤2

Step-by-step explanation:

I'm pretty sure this is the answer but it's been a while since I've done system of inequalities. Essentially the value and number of dimes is less than the value and number of quarters. And the value of both is less than or equal to 2 dollars