Answer:
<h3>dn = -7^n-1</h3>
Step-by-step explanation:
Given the sequence -1,-7,-49,-343,....
We are to find the nth term of the sequence
dn = ar^n-1
a is the first term = -1
r is the common ration = -7/-1 = -49/-7 = 7
n is the number of terms
Substitute
dn = -1(7)^n-1
dn = -7^n-1
hence the nth term of the sequence is dn = -7^n-1
The question is incomplete, here is the complete question:
Recall that m(t) = m.(1/2)^t/h for radioactive decay, where h is the half-life. Suppose that a 500 g sample of phosphorus-32 decays to 356 g over 7 days. Calculate the half life of the sample.
<u>Answer:</u> The half life of the sample of phosphorus-32 is 
<u>Step-by-step explanation:</u>
The equation used to calculate the half life of the sample is given as:

where,
m(t) = amount of sample after time 't' = 356 g
= initial amount of the sample = 500 g
t = time period = 7 days
h = half life of the sample = ?
Putting values in above equation, we get:

Hence, the half life of the sample of phosphorus-32 is 
Answer:
y=3x-10
Step-by-step explanation:
When you have to find a parallel line, you take the slope of the other line, so we already know y=3x+b. Then, plug in 2 and -4 as your x and y values and you get -4=3(2)+b. Then solve 3×2=6, so -4=6+b, subtract 6 from both sides, -10=b.