Answer:
Area = 406
Step-by-step explanation:
First things first: Divide the shape
Here is how I did it:
21 x 16
14 x 5
Now solve:
21 x 16 = 336
14 x 5 = 70
Now add:
336 + 70 = 406
So the area is 406
Answer:
12
Step-by-step explanation:
Answer:
9
Step-by-step explanation:
x-5+7=11
First think of what +7 = 11 then subtract by 5
check :)
The answer is 28 years
At = A0 * e^(-k * t)
At = 12 g
A0 = 15 g
k = 7.9 × 10^-3 = 0.0079
t = ?
12 = 15 * e^(-0.0079 * t)
12/15 = e^(-0.0079 * t)
0.8 = e^(-0.0079 * t)
Logarithm both sides (because ln(e) = 1:
ln(0.8) = ln(e^(-0.0079 * t))
ln(0.8) = (-0.0079 * t) * ln(e)
-0.223 = -0.0079 * t
t = -0.223 / -0.0079
t = 28.23
t ≈ 28 years
