Question

polynomial expansion problem, how would I approach this?

Answer 1

there will be terms which will cancel each other
Find a pattern

Answer 2

you may consider b+c=d for some simplification

Answer 3

use binomial/multinomial theorem

Answer 4

yeah if you're not familiar with the multinomial theorem it's not too hard to just use the binomial theorem twice here

Answer 5

Cool,what answer u got? :O
@imqwerty @nuts