Answer:
1. 1343 years
2. 9 hours
3. 39 years
Step-by-step explanation:
1. Given, half-life of carbon = 5730 years.
∴ λ = 0.693/half-life of carbon = 0.693/5730 = 0.000121
If N₀ = 100 then N = 85
Formula:- N = N₀*e^(-λt)
∴ 85 = 100 * e^(-0.000121t)
∴㏑(-0.85)=-0.000121t
∴ t = 1343 years
2. Given half-life of aspirin = 12 hours
λ = 0.693/12 = 0.5775
Also N₀ = 100 then 70 will disintegrate and N = 30 will remain disintegrated.
∴ 70 = 100 *e^(-0.05775t)
0.70 = e^(-0.05775t)
㏑(0.70) = -0.05775t
∴ t = 9 hours
3. The population of the birds as as A=A₀*e^(kt)
Given that the population of birds fell from 1400 from 1000, We are asked how much time it will take for the population to drop below 100, let that be x years.
The population is 1400 when f = 0, And it is 1000 when f = 5
We can write the following equation :
1400 = 1000e^(5t).
∴1400/1000 = e^(5k)
∴ k = ㏑(1.4)/5
We need to find x such that 1400/100 = e^(xk)
14 = e^(xk)
∴ x = 39 years
Answer:
D
Step-by-step explanation:
Answer:
(4x-1)(4x-1)
(x-6)(x+5)
(3x-7)(3x+7)
(3x-1)(x+6)
Step-by-step explanation:
yes
Answer:
1 squared and 1 x squared
Step-by-step explanation:
Answer: 30 m ; (or, write as: "30 meters") .
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Explanation:
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Area of a trapezoid, "A" = (1/2) ( b₁ + b₂) h ;
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or, write as: A = ( b₁ + b₂) h / 2 ;
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in which: A = area;
b₁ = length of "base 1" (choose either one of the 2 (two bases);
b₂ = length of "base 2" (use the base that is remaining);
h = height of trapezoid;
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From the information given:
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A = 100 m² ;
h = 5 m
b₁ = 10 m
b₂ = x
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Find "x", which is: "b₂" ;
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A = ( b₁ + b₂) h / 2 ;
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Plug in our known values; and plug in "x" for "b₂" ; and solve for "x" ;
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100 m² = [(10m + x) (5m)] / 2 ; Solve for "x" ;
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(10m + x) (5m) = (2)* (100m²) ;
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(5m) (10m + x) = 200 m² ;
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Note: The distributive property of multiplication:
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a(b+c) = ab + ac ;
a(b−c) = ab <span>− ac ;
</span>____________________________________________
We have: (5m) (10m + x) = 200 m² ;
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So: (5m) (10m + x) = (5m*10m) + (5m * x) ;
= 50m² + (5m)x ;
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→ 50m² + (5m)x = 200m² ;
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Divide the ENTIRE equation by "5m" ;
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→ { 50m² + (5m)x } / 5m = (200m² / 5m) ;
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→ 10m + x = 40m ;
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Now, subtract "10m" from EACH side of the equation; to isolate "x" on one side of the equation; and to solve for "x" ;
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→ 10m + x − 10m = 40m − 10m ;
to get:
→ x = 30 m ; which is our answer.
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Answer: 30 m ; (or, write as: "30 meters") .
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