Answer:0.75 milligrams will be present in 24 hours
Step-by-step explanation:
Step 1
The formula for radioactive decay can be written as
N(t)=No (1/2)^(t/t 1/2)
where
No= The amount of the radioactive substance at time=0=milligrams
t 1/2= the half-life= 6 hours
t=24 hours
N(t) = the amount at time t
Step 2--- Solving
N(t)=No (1/2)^(t/t 1/2)
=N(t)=12 x ( 1/2) ^ (24/6)
= 12 x (1/2) ^4
= 12 x 0.0625
= 0.75 milligrams
Let S be the amount in a savings account.
Let m be the number of months.
General equation
S = 132 + 27m
Specific question
July is the 7th month of the year including both January and July.
S = 132 + 7*27
S = 132 + 189
S = 321
Reasonableness?
Good question. You could estimate an answer.
Start with 150 dollars and say that you add 25 a month.
7 * 25 = 175
S = 150 + 175 = 325 All of this was done in my head. Since the exact answer obtained using the formula is 321, I think that's pretty reasonable using my estimate is a guide.
Answer:
19
Step-by-step explanation:
y = 6x - 11 If x = 5
y = (6*5) - 11
y = 30 - 11
y = 19
we have
<u>The system of equations</u>
-------> equation 
-------> equation 
Substitute equation
in equation 

subtract
both sides


Divide by
both sides

the solution is the point 
therefore
the answer is
the solution to the system of equations is the point 