Find the number of terms when the expression (1 + x)^10*(1 - x)^10 is expanded completely.
This is equal to (1-x²)¹⁰, since (1+x)^10 x (1-x)^10 = ((1+x)(1-x))^10.
A binomial raised to any power n has n+1 terms (assuming nothing simplifies).
There will be 10+1= 11 terms upon combining all like terms (I think).