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:
8
Step-by-step explanation:
3x is a varable and -1 is an integer
Answer:
bank account cant give me 5 bank name
Answer:
416 g
Step-by-step explanation:
The mean is calculated as
mean =
, then
= 398 ( multiply both sides by 5 )
sum of 5 pods = 1990 g
let x be the weight of the sixth pod , then
= 401 ( multiply both sides by 6 )
1990 + x = 2406 ( subtract 1990 from both sides )
x = 416
That is the weight of the sixth pod is 416 g