She spent 17 hours tutoring
$210 = 7 hours
$20 x 10 hours = $200
$210 + $200 = $410
7 Hours + 10 Hours = 17 Hours
I believe that the answer would be 45
I think is letter A l hope it works.
Answer:

Step-by-step explanation:
The standard charge includes an initial fee and plus an addditional fee for each mile driven and is given by:

The insurance charge is given by:

So, the total charge C will be the sum of the standard charge S and the insurance charge I:

Substitute:

Rearrange:

Add:

And we have acauired our equation relating C to M!
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

