> OK I remember it now. Here is how you do it.
>
> [3 + (2a + b)]Č
>
> first take out the brackets and the Č means multiply it by itself so
>
> (3 + 2a + b)(3 + 2a + b)
>
> Now you jump the multiplications, first take the first 3 and distribute it into each
> thing in the second parentheses then do the same with the 2a and b so
>
> (3*3) + (3*2a) + (3*b) + (2a*3) + (2a*2a) + (2a*b) + (b*3) + (b*2a) + (b*b)
>
> =
>
> 9 + 6a + 3b + 6a + 4aČ + 2ab + 3b + 2ab + bČ
>
> then combine like terms
>
> 9 + 12a + 6b + 4aČ +4ab + bČ
You can also arrange it in a grid like this:
3 2a b
---------------
3 | 9 | 6a | 3b |
---------------
2a | 6a | 4aČ| 2ab |
---------------
b | 3b | 2ab| bČ |
---------------
Then add up everything inside the grid.
Plain numbers: 9 = 9
Multiples of a: 6a + 6a = 12a
Multiples of b: 3b + 3b = 6b
Multiples of ab: 2ab + 2ab = 4ab
Multiples of aČ: 4aČ = 4aČ
Multiples of bČ: bČ = bČ
Grand total: 9 + 12a + 6b + 4ab + 4aČ + bČ
Edited by amused (03/20/13 05:32 PM)