Answer:
113 is correct because 49 divided by 3 is 16.33. 16.33 multiplied by 7 is 113
Step-by-step explanation:
<span>8 + 5n = -72
5n = -72 - 8
5n = - 80
n = -80/5
n = -16</span>
Answer:
x = 53
Step-by-step explanation:
Remember that the sum of all 3 interior angles in a triangle is 180∘ so
74 + x + x = 180
74 + 2x = 180
2x = 180 - 74
2x = 106
x = 106/2
x = 53
I assume you happen to mean, what is the formula for a circle.
The formula is:
A=
Answer:
Step-by-step explanation:
For a first order decay, fraction remaining = 0.5n where n = number of half lives elapsed.
fraction remaining = 55% = 0.55
0.55 = 0.5n
log 0.55 = n log 0.5
-0.2596 = -0.301 n
n = 0.8625 = # of half lives elapsed
0.8625 half lives x 2.5 billion years/half live = 2.16 billion years have elapsed = age of the rock
b) 0.15 = 0.5n
log 0.15 = n log 0.5
-0.824 = -0.301 n
n = 2.74 half lives
2.5 billion years/half life x 2.74 half lives = 6.85 billion years = age of rock
