Answer:
set mary is x years old, and helen is y years old.
first sentence:x=2y
second one:4(y-8)=x+4
bring x=2y in 4(y-8)=x+4
=>4y-32=2y+4
=>2y=36
=>y=18
=>x=36
mary:36
helen:18
Answer: 6 1/6
Step-by-step explanation:
1) First divide 10 1/2 = 5 1/4.
2) Then, since we divide 10 1/2 then we need to divide 12 1/3.
3) 12 1/3 divided by 2 = 6 1/6.
And there is your answer; 6 1/6
8x+324 is the answer, all you have to do is multiple 6 times 54
To find midpoint, we find the average or median of the two x terms and the average of the two y terms to find the right coordinate point. In this case, the average of -2 and 6 is 2, and the mean of 4 and -4 is 0, so the new coordinate point is (2,0).
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

