16 because if you put 16 into a percentage it's 80. 16 divide 20 times 100 equal 80
Answer:
-5
Step-by-step explanation:
Let n be the unknown number
difference is subtraction
3n -4 = -19
Add 4 to each side
3n-4+4 = -19+4
3n = -15
Divide by 3
3n/3 = -15/3
n = -5
<span> half life i= 78 hours
amount after 78 hours is 395 kg:
395 = 790e^(k*78)
Dividing by 790 and taking natural log
ln (395/790) = (k*78)
-0.6931 = 78k
-0.00888 = k
lets calculate how much is left after 18 hours:
Amount(18)
= 790e^(-0.00888*18)
Amount = 673.301 kg
hope this helps</span>
Answer: 20
Reason: They're opposite meaning they are the same when compared to the side
