Please no links!! Can’t open them! Thanks

Answer:

The lab will have to wait 19.45 yers to safely store the material before disposal.

Step-by-step explanation:

Exponential equation for substance decay:

A exponential equation for the amount of a substance after t years is given by:

[tex]A(t) = A(0)(1-r)^{t}[/tex]

In which A(0) is the initial amount and r is the decay rate, as a decimal.

Decays at 3.5% per year.

This means that [tex]r = 0.035[/tex]

So

[tex]A(t) = A(0)(1-r)^{t}[/tex]

[tex]A(t) = A(0)(0.965)^{t}[/tex]

How many years will the lab have to safely store the material before disposal?

It needs to reach half-life, that is, t for which A(t) = 0.5A(0). So

[tex]A(t) = A(0)(0.965)^{t}[/tex]

[tex]0.5A(0) = A(0)(0.965)^{t}[/tex]

[tex](0.965)^t = 0.5[/tex]

[tex]\log{(0.965)^t} = \log{0.5}[/tex]

[tex]t\log{0.965} = \log{0.5}[/tex]

[tex]t = \frac{\log{0.5}}{\log{0.965}}[/tex]

[tex]t = 19.45[/tex]

The lab will have to wait 19.45 yers to safely store the material before disposal.

Answer:

4(10+9) - 40 + 36

9(5+2) - 45 + 18

3(12+7) - 36 + 21

Answer:

look at the picture i sent..........

Answer:

He is wrong

Step-by-step explanation:

£1.30(cost of 1 egg box) x 2=£2.60

2.60(2 egg boxes)+2.60(price of juice)=£5.20(amount spent without baguettes)

10-5.20(amount spent without baguettes)=£4.80

4.80/3=£1.60

£1.60=cost of one baguette

Sam is wrong as the cost of one baguette is £1.60

Answer:

I think its B or C

Step-by-step explanation:

Answer:

V = 255.98189 pi

SA = 172.64114π

Step-by-step explanation:

The first thing to do is find the radius.

the measure of angle AKO = 1/2 the measure of angle AKB

m< AKO = 12.5 degrees

Now use trig to find AO (aka the radius)

tan(12.5) = AO/25

AO = 25* tan(12.5)

I'm leaving it like this to get a more accurate number

Now to find the volume

the volume of a cone is pir^2h/3

plugging everything in we get:

pi(25*tan(12.5))^2 * 25/3

which is about 255.98189 pi

Now for surface area

(this is the moment I realize symbols exist)

SA = πr(r+√h²+r²)

plugging everything in we have

π(25tan(12.5))((25tan(12.5)+√625+(25tan(12.5))^2)

I know it looks like a lot but that's mainly because I left the radius as 25tan(12.5)

The Surface Area is about 172.64114π

Answer:

look at the picture i sent

Answer:

0

Step-by-step explanation:

use mathaway :D

Answer:

try dividing 161616 with 7 but I don't know what to do with the 6 sorry

Answer:

y=−1.5x−7

Step-by-step explanation:

mr. mole is descending as a constant rate, which means a linear equation. So, we must put it into slope-intercept form: y=mx + b, with m being slope or constant rate, and b being y-intercept

Answer:

x = 49

Step-by-step explanation:

This is an inverse relationship and it implies that, an increase in the value of one variable results in a subsequent decrease in the value of another variable.

Given the mathematical expression and data;

y = 1/√x

y = 7 and x = 64

First of all, we would find the constant of proportionality, k;

y = k/√x

7 = k/√64

7 = k/8

k = 7 * 8

Constant, k = 56

Now, to find the value of x when y = 8

y = k/√x

Substituting the values, we have;

8 = 56/√x

Cross-multiplying, we have;

8 * √x = 56

√x = 56/8

√x = 7

Taking the square of both sides, we have;

(√x)² = 7²

x = 49

Answer:

nos etu  mdei

Step-by-step explanation:

Answer:

33in squared, so B

Step-by-step explanation:

the area of a triangle is (Base x height)/2

The area of a square is just length x width

Now solve

since each triangle is the same and there a 4 triangles do

4(3x4) which is 4(12)

4 x 12= 48

48/2= 24

3 x 3 for the square

24+9=33

Hope this helps!

Answer:

Hope it helps

Step-by-step explanation:

3/4(7/7)=21/28

1/2(8/8)=8/16

4/9(2/2)=8/18

2/5(9/9)=18/45

6/3(6/6)=36/18

3/2(7/7)=21/14

PLS RATE AS BRAINLIEST

Answer:

16a

Step-by-step explanation:

4a+12a=16a since they are the same variables.

Answer:

Adeles forgot to square root 25 in step 4 therefore the solutions would be 1 and -9

Step-by-step explanation:

Equation : x² + 8x - 9 = 0

Step 1 : x² + 8x = 9

Step 2 :  x² + 8x + 16 = 9 + 16

Step 3 :  ( x + 4 )² = 25

Step 4 :  x + 4 = 25 or x + 4 = - 25

Step 5 :  x = 21 or x = - 29.

Answer: need more of an explanation

Step-by-step explanation:

Answer:

26 in.

Step-by-step explanation:

Since angles A and C are congruent, sides BC and BA are congruent.

7x - 13 = x + 29

6x = 42

x = 7

AC = 3x + 5

AC = 3(7) + 5

AC = 21 + 5

AC = 26

Answer: 26 in.

Answer:

C. a = 1, b = 8, c = -3

Step-by-step explanation:

.........

Answer:

By decreasing the production time for textiles

Step-by-step explanation:

Answer:

yes

Step-by-step explanation:

Answer:

three and four-eighths inches

Step-by-step explanation:

Given :

Tick 1 = 2/8 (1 data point)

Tick 2 = 3/8 (3 data points)

Tick 3 = 4/8 (2 data points)

Tick 4 = 5/8 (no points)

Tick 5 = 6/8 (2 data points)

Tick 6 = 7/8 (no data points)

Tick 2 = 3/8 (3 data points)

....

Tick 13 = 1 6/8 (2 data points)

Hence, total length of all meteors that are 1 6/8 inches :

Length of meteor = 1 6/8

Number of meteors = 2

(2 * 1 6/8) = 2 * 14/8 = 28/8 = 3 4/8 = 3 1/2

Answer:

three and four-eights inches

Step-by-step explanation:

Answer:

the answer is mai is 54 and lin is 59

Answer:

[tex] - 1710[/tex]

Step-by-step explanation:

[tex] - 114 \times 15 \\ = - 1710[/tex]

Answer:

D

Step-by-step explanation:

Answer:

athe correct answer of this question is 6x + 3y = 5

Answer:

Each friend will get a half of a sandwich

Step-by-step explanation:

1 friend            1 friend

1 friend            1 friend

(split the two sandwiches in half)

Now you have 4 halfs to give to your 4 friends

Answer: 44

Step-by-step explanation:

Answer:

3(2)+7(2)-9(2)+4(2)+10+12(2)

6+14-18+6+10+24

60-18

42

Answer:

. (a) A scientist is doing an experiment on bacteria. She finds that the number ofbacteria in a test tube increase at a rate of 0.9% per hour.At 12 noon there are 4500 bacteria.At 3 pm, how many bacteria will be present? Give your answer to 3 significantfigures.

12pm 4500 bacteria1pm 4500 x 1.009 bacteria 2pm 4500 x 1.009 x 1.009 bacteria3pm 4500 x 1.009 x 1.009 x 1.009 bacteriaTherefore at 3pm there are 4620 bacteria present.

Answer: 4620 (3)(b) In another experiment with the same bacteria, the scientist counts 3000 bacteria.How many bacteria were there two hours prior to this measurement?Give your answer to 3 significant figures.

Now 3000 bacteria1 hour ago 3000 ÷ 1.009 bacteria 2 hours ago 3000 ÷ 1.009 ÷ 1.009 bacteriaTherefore 2 hours ago there were 2950 bacteria present

Answer: 2950

Step-by-step explanation:

Answer:

x= 3/4

Step-by-step explanation:

x-1/4=1/2

 +1/4  +1/4

x=3/4