Answer:

Step-by-step explanation:

I am joyous to assist you anytime.
If the question is, what is it? It is called this figure a pencil of lines.
А pencil of lines can consist of any number of straight, the main thing that they all had one common point. Here you can find a lot of vertical angles and rays.
Let

Differentiating twice gives


When x = 0, we observe that y(0) = a₀ and y'(0) = a₁ can act as initial conditions.
Substitute these into the given differential equation:


Then the coefficients in the power series solution are governed by the recurrence relation,

Since the n-th coefficient depends on the (n - 2)-th coefficient, we split n into two cases.
• If n is even, then n = 2k for some integer k ≥ 0. Then




It should be easy enough to see that

• If n is odd, then n = 2k + 1 for some k ≥ 0. Then




so that

So, the overall series solution is


To estimate you would round the numbers, so it would be 7,000 - 4,000 = 3,000.
length = 1/2 w+9
perimeter= 60 =2(l+w)
substitute in for length
60 = 2(1/2 w +9 +w)
60 = 2 (3/2 w +9)
distribute
60 = 3w + 18
subtract 18 from each side
42 = 3w
divide by 3 on each side
14 = w
length = 1/2 w + 9
length = 1/2 (14) +9
7 + 9
16cm