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:
Therefore the population will be maximum when x=30 inches.
Step-by-step explanation:
Given that, the mosquito population is a function of rainfall and can be approximated by the formula
where x is the number of inches of rainfall.
Differentiating with respect to x
Again differentiating with respect to x
Now we set N'(x)=0
Since at x=30, N''(x)<0, So at x=30, N(x) has maximum value.
Therefore the population will be maximum when x=30 inches.
Answer:
1,12 is your answer 1, 2x6-12
Step-by-step explanation:
Answer:
27 and 16
Step-by-step explanation:
x + y = 43
x - y = 11
You can add up the two equations so the ys are cancelled out.
2x = 54
x = 27
Plug x in to find y.
27 - y = 11
y = 16
Answer:
Part 1) The perimeter is 
Part 2) The diagonal is 
Step-by-step explanation:
<u><em>The question in English is</em></u>
You have a rectangle whose base is twice the height and its area is 12
square centimeters. Calculate the perimeter of the rectangle and its diagonal
step 1
Find the dimensions of rectangle
we know that
The area of rectangle is equal to
so
----> equation A
The base is twice the height
so
----> equation B
substitute equation B in equation A
Find the value of b
step 2
Find the perimeter of rectangle
The perimeter is given by
substitute
step 3
Find the diagonal of rectangle
Applying the Pythagorean Theorem
substitute
