Since there is a common difference of one, this is an arithmetic sequence of the form a(n)=a+d(n-1) which in this case is:
a(n)=15+1(n-1)
All arithmetic sequences have a sum which is equal to the average of the first and last terms time the number of terms, mathematically:
s(n)=(2an+dn^2-dn)/2 (that is just the result of ((a+a+d(n-1))(n/2)) )
Since a=15 and d=1 this becomes:
s(n)=(30n+n^2-n)/2
s(n)=(n^2+29n)/2 so
s(10)=(100+290)/2
s(10)=195 logs
Answer:
D
Step-by-step explanation:
Answer:
5 8/15 Gallons
Step-by-step explanation:
Step 1: Change mixed numbers into improper fractions.
14 1/5 = 71/5
8 2/3 = 26/3
Step 2: Change the improper fractions to have the same denominator.
71/5 = 213/15
26/3 = 130/15
Step 3: Subtract
213/15 - 130/15 = 83/15
Step 4: Simplify
83/15 = 5 8/15
Hope this helps! :D
Answer:
5 10
12 5
Step-by-step explanation:
you add numbers in the same position.
2+3. 4+6
7+5. 5+2
Answer:
The substance half-life is of 4.98 days.
Step-by-step explanation:
Equation for an amount of a decaying substance:
The equation for the amount of a substance that decay exponentially has the following format:
In which k is the decay rate, as a decimal.
k-value of 0.1392.
This means that:
Find the substance's half life, in days.
This is t for which 
. So
The substance half-life is of 4.98 days.
