If Chad drove 168 miles in 2 hours, how many hours will it take Chad to drive 840 miles traveling at the same rate?

10 hours

Step-by-step explanation:

First we need to find the rate Chad is driving. The rate is equal to distance/time, so we do 168/2, which is 84 mph. Then we have to find the time, which is distance/rate, so that would be 840/84, which is 10 hours.

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