Since this is exponential decay we can express it as:
f=ir^t, f=final amount, r=common ratio, t=time
If the half life is 140 days we can say:
a/2=ar^140
.5=r^140
r=.5^(1/140) now we can express our equation as:
f=i(.5^(1/140))^t which is equal to:
f=i(.5)^(t/140) now we want to find the time necessary to reduce 300mg to 200mg so:
200=300(.5)^(t/140) divide both sides by 300
2/3=.5^(t/140) taking the natural log of both sides
ln(2/3)=(t/140)ln.5 divide both sides by ln.5
ln(2/3)/ln.5=t/140 multiply both sides by 140
t=140ln(2/3)/ln.5
t≈81.89 days (to the nearest hundredth of a day)
9=n+3
Subtract 3 on each side
n=6
I believe the answer to this is 3/2
Answer:
Step-by-step explanation:
Given
Required
Determine the sales price
First, we calculate the discount price
The sales price is then calculated by subtracting the discount price from the original price of the item
98-7x=3x+18. -7x-3x=-98+18. -10x=-70. X=7.
