Answer:
D. 70°
Step-by-step explanation:
the sum of the unknown angle and 110° is 180 °
so, let the unknown angle be x
x+110 = 180
x = 180-110
x = 70°
Answer:
Attached file
Step-by-step explanation:
<span>2(7/9)-(1/4) = 47/36 = 1 11/36</span>
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