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:
A is for apple
Step-by-step explanation:
abc
Answer:
27
Step-by-step explanation:
Given that the total number of people protesting is 81. These people are either male - Student or non student or Females (student or non students)
Given that there are 36 males then number of females
= 81 - 36
= 45
If there are 18 females non students then the number of females protesting that are students
= 45 - 18
= 27
First, the factor pairs for 18 are:
1, 18
2, 9
3, 6
Since the middle term is -3, the two factors must be 3 apart. The only pair that is 3 values apart is 3, 6.
Since the middle value is negative, the larger number is negative. This means that the 6 is negative.
z = -6
z = 3
Set each equal to 0;
z = -6
z + 6 = 0
z = 3
z - 3 =0
So your factors are (z+6) and (z-3), or answer B.
