Erik rode down an escalator, while raj rode up.
erik's elevation is represented by the equation h = 12 – 0.75t, and raj's elevation is represented by h = 0.75t. what does the point of intersection on the graph represent?

1) 2/5

2) zero=0/1

3) zero=0/2

4) -4/5

5) undefined=3/0

sounds & other waves originate from any vibrating object

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