Find the number of terms when the expression (1 + x)^10*(1 - x)^10 is expanded completely.
Note that a^10 * b^10 = (ab)^10....so
(1 + x) ( 1 - x) = ( 1 - x^2)
So
( 1 + x)^10 * ( 1 - x)^10 =
( 1 - x^2) ^10
And by the Binomaial Expansion ....... ( a + b)^n will have n + 1 terms
n + 1 = 10 + 1 = 11 terms
