Answer:
9
Step-by-step explanation:
If you want to get $15 profit, You will need to paint 9 faces. You spent $12 on painting supplies so this is the explanation.
$3 x 9 = $27
$-12 + $27 = $15
That way, you earn $15.
30×4=120 then multiply 75×4=340 then add 120+340=460
Answer:
first one: B and C
Second one: x=12, y=10 so the answer is B.
Step-by-step explanation:
First one: Irrational numbers are any numbers that go on forever in the decimal without ever repeating. Any square roots of numbers that aren't perfectly square, such as 4 and 9, are irrational. And anything with pi, or 
, is always irrational.
Second one: 144 and 100 are perfect squares, meaning it can be created by multiplying the same number by itself, in this case 12 and 10. Subtract those and you get 2.
(a) Assuming that Q satisfies the differential equation Q' = -rQ, determine the decay constant r for carbon-14. (b) Find an expression for Q(t) at any time t, if Q(0) = Qo. (c) Suppose that certain remains are discovered in which the current residual amount of carbon-14 is 20% of the original amount. Determine the age of these remains.
Answer:
a) r = (In 2)/(t1/2) = (In 2)/5730 = 0.000121/year
b) Q(t) = Q₀ (e^-rt)
c) Are of the 20% remnant of Carbon-14 = 13301.14 years.
Step-by-step explanation:
Q' = -rQ
Q' = dQ/dt
dQ/dt = -rQ
dQ/Q = -rdt
Integrating the left hand side from Q₀ to Q₀/2 and the right hand side from 0 to t1/2 (half life, t1/2 = 5730 years)
In ((Q₀/2)/Q₀) = -r(t1/2)
In (1/2) = -r(t1/2)
In 2 = r(t1/2)
r = (In 2)/(t1/2) = (In 2)/5730 = 0.000121 /year
b) Q' = -rQ
Q' = dQ/dt
dQ/dt = -rQ
dQ/Q = -rdt
Integrating the left hand side from Q₀ to Q(t) and the right hand side from 0 to t.
In (Q(t)/Q₀) = -rt
Q(t)/Q₀ = e^(-rt)
Q(t) = Q₀ (e^-rt)
c) Q(t) = Q₀ (e^-rt)
Q(t) = 0.2Q₀, t = ? and r = 0.000121/year
0.2Q₀ = Q₀ (e^-rt)
0.2 = e^-rt
In 0.2 = -rt
-1.6094 = - 0.000121 × t
t = 1.6094/0.000121 = 13301.14 years.
Hope this Helps!
Answer:
2
Step-by-step explanation:
60/30 is 2
HOpe this helps :D
PLz mark brainliest if correct :D
