Answer:
see explanation
Step-by-step explanation:
the sum to n terms of an arithmetic sequence is
=
[2a + (n - 1)d ]
where d is the common difference and a is the first term
here d = 9 - 7 = 7 - 5 = 2 and a = 5, hence
=
[(2 × 5) + 2(n - 1) ]
=
(10 + 2n - 2)
=
(2n + 8)
= n² + 4n
When sum = 165, then
n² + 4n = 165 ← rearrange into standard form
n² + 4n - 165 = 0 ← in standard form
(n + 15)(n - 11) = 0 ← in factored form
equate each factor to zero and solve for n
n + 15 = 0 ⇒ n = - 15
n - 11 = 0 ⇒ n = 11
but n > 0 ⇒ n = 11
S=d/t so in this case it's 75/12 which is 6.25. Round it and you got 6 miles per hour.
Answer:
this is the answer
Step-by-step explanation:
So to start subtract $5 from $16.25 for the monthly membership
That gives you $11.25
So then you Just divide...
$11.25 divided by $1.25
which gives you 9
So bill rented 9 movies for the month
Hope this helped! :)
Hello,
Let's assume n,n+1,n+2,n+3,n+4 the 5 numbers
n+(n+1)+...+(n+4)=5n+10=265
5n=265-10
5n=255
n=51
The 5th number is 51+4=55