39. 7 times 5 equals 35 plus 4 equals 39 :)
X-5= 20
x-5= -20
Absolute value makes a negative positive, so when you are solving x-5 could have been 20 originally or -20 originally. Solve for both.
Hey there!
The x-intercept would be positive 3 because it is the opposite of -3 in the equation.
And the y-intercept would be -4.
I hope this helps you :)
Answer:
no
Step-by-step explanation:
The set of perfect squares includes {0, 1, 4, 9, 16, 25, ...}.
Subtracting a couple of the elements, we get ...
4 - 1 = 3 . . . . not a member of the set
The set is NOT CLOSED under subtraction.
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
