The radius of a circle is 18 inches. A snail crawls along the diameter of the circle at a rate of 3 inches per minute. How long does it take the snail to make the trip?

12 minutes

Step-by-step explanation:

The radius is half the diameter, so 18*2 = 36 inches

The diameter is 36 inches.

Divide the diameter by the rate, 36/3 = 12 minutes

Your answer is 12 minutes

hello from mrbilldoesmath!

answer:

(7 x + 6 y) (49 x^2 - 42 x y + 36 y^2)

discussion:

the trick is to recognize that 343 = 7^3 and 216 = 6^3 and, in general,

a^3 + b^3 =   (a + b) (a^2 - a b + b^2).

in our case

343x^3+216y^3   =   (7x)^3 + (6y)^3

so take a = 7x and b = 6y in the above equation to get the answer.

you,

mrb