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
Answer:
She can play 7 games
Step-by-step explanation:
Substrate 4 from 25
The answer is D.
Explanation- 28/7=4
19-4 =15
Answer: He was 1 minute 28 seconds faster.
Step-by-step explanation:
Hi, to answer this question we simply have to subtract Frankie's time yesterday (29 minutes 49 seconds) to his normal time (31 minutes 17 seconds)
Mathematically speaking:
31m 17s - 29m 49s =
(31m-29 m) (17s-49s)=
2m -32s=
1m 60s -32s=
1m 28s
He was 1 minute 28 seconds faster.
Feel free to ask for more if needed or if you did not understand something.
Feel free to ask for more if needed or if you did not understand something.
Answer:
$6,900
Step-by-step explanation:
Let
x = Amount Monica should earn each month
Rent per month = $2,300
Monica knows that she should spend no more than 1/3 of her income on her rent
1/3 of her Income = rent
1/3 of x = 2,300
1/3x = 2,300
x = 2,300 ÷ 1/3
x = 2,300 * 3/1
x = $6,900
Monica should earn $6,900 each month to afford the rent on her cool new place