Cost of the lawnmower bought by Sarah = $320
Amount of down payment made by Sarah = $100
Amount paid by Sarah in 12 months = (12 * 25) dollars
= 300 dollars
Total amount paid by Sarah = (300 + 100) dollars
= 400 dollars
Excess amount paid as interest by Sarah = (400 - 320) dollars
= 80 dollars
Actual yearly rate of interest paid by Sarah = (80/320) * 100 percent
= 25 percent
So 25% yearly interest was paid by Sarah. The correct option is option "C".
Answer:
(16+25)×47
Step-by-step explanation:
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Answer:
a) Y(x) = {900, x≤30; 900-40(x-30), x>30}
b) T(x) = {900x, x≤30; 2100x-40x², x>30}
c) dT/dx = {900, x≤30; 2100-80x, x>30}
Step-by-step explanation:
a) The problem statement gives the function for x ≤ 30, and gives an example of evaluating the function for x = 35. So, replacing 35 in the example with x gives the function definition for x > 30.

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b) The yield per acre is the product of the number of trees and the yield per tree:
T(x) = x·Y(x)

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c) The derivative is ...

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The attached graph shows the yield per acre (purple, overlaid by red for x<30), the total yield (black), and the derivative of the total yield (red). You will note the discontinuity in the derivative at x=30, where adding one more tree per acre suddenly makes the rate of change of yield be negative.
22 kilometers :) hope that helped