Answer:
Step-by-step explanation:

(15a^4 - 30a^5 )/5a^2
= 5a^2(3a^2 - 6a^3) / 5a^2
= 3a^2 - 6a^3
or
= - 6a^3 + 3a^2
We estimate the diameter of the larger wheel to be 24 to 25 inches.
The formula for the Circ. of a circle in terms of the diameter is C = pi*d.
Here, the Circ. of the larger wheel is approx C = pi(24 inches) = 24*pi inches,
or
24(3.14) inches = 75.36 inches. You must now choose from the four answer choices. Which one is closes to 75.36 inches?
Square root of (5-9)^2+(1+6)^2