The three altitudes of δabc intersect at point f. point f is the
a) centroid.
b) circumcenter.
c) incenter.
d) orthocenter.

The answer would be D-orthocenter

Step-by-step explanation:

The definition for orthocenter is the point where 3 altitudes of a triangle intersect. (inside my math vocab)

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