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:
3. 9 - (n ÷ 5 ) 5. 8 x ( 5 x t ) (( i don't know the others ))
Step-by-step explanation:
Answer:
By factoring we get:
(x -9) * (x -9) = 0
The answers are
x = 9 and x = 9
Step-by-step explanation:
The answer would be B because he is gonna babysit for 4 hours and will charge $40 plus $4. So for the 4 hours he will earn $16 plus 40.
500 Because 35/7 = 5 and 5*100 (100%) = $500
Good Luck!
