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ira [324]
3 years ago
10

A toxic radioactive substance with the density of 4 mg/cm² is detected in the been detected in the ventilating ducts that was us

ed 35 years ago. if the half-life of substances 20 years what is the density of a substance when it was deposited 35 years ago
Mathematics
1 answer:
Kruka [31]3 years ago
8 0
The formula for half-life is:

A = P(0.5)^{t/h}

A is the amount remaining, P is the initial amount, t is the time that has passed, and h is the half-life of the substance.  Plug in the values that you know and solve:

4 = P(0.5)^{35/20} \\ \\ 4 = P(0.5)^{1.75} \\ \\ P = \frac{4}{0.5^{1.75}} \\ \\ P \approx 13.4543426441

Rounded to the nearest whole number, the density of the substance was about 13<span>mg / cm².</span>
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I need these 2 questions answered please.​
Sav [38]

The area of the circle is 28 ft square.

The area of the triangle is 30 ft square.

Step-by-step explanation:

1) The area of the circle= π*r^2

where π= 3.14(default value) and "r" is the radius of the circle.

Here, Radius of the circle(r)= 3 ft

Area = 3.14*3*3

        = 28.26 ft sq.= 28 ft sq(rounded to the nearest whole number)

2) The triangle has the base= 10 feet and height= 6 feet

The Area of the triangle= 1/2(b)(h)

where "b" is the base and "h" is the height of the triangle.

Substitute b=10 and h=6 ,

Area of triangle= 1/2(10 ft)(6 ft)= 60/2= 30 feet sq.

5 0
3 years ago
WILLL MARK BRAINLIST......<br> 4.71 x 0.2 I NEED STEP BY STEP ON HOW TO SOLVE
OverLord2011 [107]

Answer:

Put 4.71 over 0.2 and make sure to line up the decimal.

4.71

<u>x 0.2</u>

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Step-by-step explanation:

8 0
3 years ago
F(x)= x squared -3x + 2 divided by 3x squared + 9 x -12
VashaNatasha [74]

Answer:

=(x-2)/3(x+4)

Step-by-step explanation:

F(x)=x²-3x+2/3x²+9x-12

Using mid term break formula

=x²-2x-x+2/3(x²+3x-4)

=x(x-2)-1(x-2)/3(x²+4x-x-4)

=(x-2)(x-1)/3{x(x+4)-1(x+4)}

=(x-2)(x-1)/3(x-1)(x+4)

Cancelling (x-1)

We get

=(x-2)/3(x+4)

Hope it helps :)

6 0
3 years ago
3(2+7) - 9 x 7 = 3+8 x 2 x 2 - 4 = 16 ÷ 2 x 5 x 3 ÷ 6 = Please answer! ✨✨
Thepotemich [5.8K]

Answer:

At first, we have 3 expressions that are equal.

3(2+7) - 9 \cdot 7= 3+8 \cdot 2 \cdot 2 - 4

6+21 - 63= 3+32 - 4

-36=31

-36\neq 31

This is not true.

3 0
3 years ago
Which one of the following is NOT true about the expression shown
garri49 [273]

Answer:

A) The expression is a trinomial.

Step-by-step explanation:

If the degree is 2, the expression would be a binomial, not a trinomial. If this answer is correct, please make me Brainliest!

7 0
3 years ago
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