5(2+h)^3

Question

5(2+h)^3

anonymous · Answer

Do you need to expand brackets?

amistre64 · Answer

5(2+h)(2+h)(2+h)

anonymous · Answer

Yes clearly but I do not see what the question is getting at.

amistre64 · Answer

its not a question so much as a chance to read minds lol

anonymous · Answer

True :)

anonymous · Answer

amistre is a mind reader for sure

amistre64 · Answer

its openstudy jeopardy; you get an answer and have to form the question ;)

anonymous · Answer

that probability question took it out of me.

amistre64 · Answer

2+h
* 2+h
-----
4 +2h
   +2h+h^2
-----------
4 +4h +h^2
         * 2+h
------------
8 +8h +2h^2
   +4h +4h^2 +h^3
-----------------
8 +12h +6h^2 +h^3
                         * 5
-------------------
40 +60h +30h^2 +5h^3

anonymous · Answer

$$(a+b)^3=a^3+3a^2b+3ab^2+b^3$$ is useful in this context

anonymous · Answer

put $$a=2,b=h$$and out it pops

anonymous · Answer

POP!

amistre64 · Answer

useful if you like to memorize formulas; but not so good if you need to know why the formula works.

anonymous · Answer

actually i think it is very useful to know $$(a+b)^n$$ unless you want to do zillions of multiplication reinventing the wheel at every step

amistre64 · Answer

after doing alot of these equations you notice a pattern that forms; and that pattern matches the formula.

You can derive the formula as well by simply using the variables instead of the numbers...

anonymous · Answer

i guess you could say it is a 'formula' but it is certainly a useful one to know.

anonymous · Answer

like memorizing 8*7=56