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snow_tiger [21]
3 years ago
6

A radioactive substance decays according to

Mathematics
1 answer:
irakobra [83]3 years ago
6 0

Answer:554.64 s

Step-by-step explanation:78/250= e^(-0.0021t)

0.312=e^(-0.0021t)

ln0.312= -0.0021t

t= 554.64 s

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A square park with sides 15 meters in length has a diagonal walkway as shown.
Alexxandr [17]

Answer:

The approximate length of the diagonal walkway is 21.21 meters

Step-by-step explanation:

we know that

Applying the Pythagorean Theorem in the square park, find out the the approximate length of the diagonal walkway

so

c^2=a^2+b^2

where

c is the diagonal of the square

a and b are the length sides of the square

we have

a=15\ m\\b=15\ m

substitute

c^2=15^2+15^2\\c^2=450\\c=21.21\ m

therefore

The approximate length of the diagonal walkway is 21.21 meters

5 0
3 years ago
Find the value of x.
alukav5142 [94]

Step-by-step explanation:

The sum of the three angles in a triangle must be 180. Since this triangle has a right angle, we know that it is 90°, so the sum of the remaining two angles must be 90.

We can set up an equation for the two remaining angles to determine the value of x:

(x + 28) + x = 90

2x + 28 = 90

2x = 62

x = 31

8 0
3 years ago
Read 2 more answers
Answer: <br> -7(k+9)=9(k-5)-14k
pav-90 [236]
-7(k+9)=9(k-5)-14k
-7k-63=(9k-45)-14k
-7k-63=-5k-45
-7k=-5k+18
-2k=18
k=-9
7 0
3 years ago
the elevator of new orleans, louisiana is on average 8 ft below sea level. the elevation of EL Centro, california is 39ft below
Svetllana [295]
The difference in elevation equals subtraction. In other words 39ft subtracted by 8ft equals 31ft. So New Orleans, Louisiana is 31ft ABOVE sea level compared to EL Centro, California.
6 0
4 years ago
Pedro deposited $7,350 into a savings account 21 years ago. The account has an interest rate of 4.5% and the balance is currentl
Licemer1 [7]
The interest is compounded quarterly because the formula is
A=p (1+r/k)^kt
A it's 18810.67 but I will assume it's unknown ?
P present value 7350
R interest rate 0.045
K compounded quarterly 4
Now solve the formula as the interest is compoundedquarterly
A=7,350×(1+0.045÷4)^(4×21)
A=18,810.67

So the answer is quarterly
5 0
3 years ago
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