Answer:
It will take approximately 3.34 hours for the drug to decay to 90% of the original dosage
Step-by-step explanation:
As suggested, we use the formula for exponential decay:
From the given information, the half life of the drug in blood id 22 hours, so that means that it takes that number of hours to go from the initial value 
, to a final value equal to 
. Using this information we can find the decay rate "k" by solving for this parameter in the formula, and using the natural log function to bring the exponent down:
Now we use this value for the decay rate "k" to calculate how long it would take to decay to 90% of the original dose;
Answer:
Slope is 1/4
Step-by-step explanation:
7h + 6b = 35.50
5h + 6b = 30.50
The difference between the 2 totals spent is $5, and there were the same number of burgers, but 2 fewer hotdogs. So $5/2 = $2.50, the cost of a hot dog. Substitute that into the equations to solve for burgers (b)
5(2.50) + 6b = 30.50
12.50 + 6b = 30.50
6b = 18
b = 3
Check the work:
7(2.50) + 6(3) =
17.50 + 18 = 35.50
Answer:
One solution
Step-by-step explanation:
They have isolated y for you in both equations so you can plug either one into the other.
y = 3x - 1
2x + 7 = 3x - 1
isolate the x
7 = x - 1
x = 8
Go back to the original and plug 8 into x to get y.
y = 2 (8) + 7
y = 16 + 7
y = 23
This means at (8, 23) y = 2x+7 is equal to y = 3x-1. In other words they share a point at (8, 23). This is the only solution because for any other x and y they'd not be equal.
Answer:
61/12a
Step-by-step explanation:
convert the mixed number 4 1/4 into a improper fraction which turns into 17/4, you then add the sum of 5/6a + 17/4a which is 61/12a
