Primitive formula

=( 1-x)( 1-x)？

=( 1-x)( 1-2x+x？ )

= 1-3x+3x？ -x？

The meaning of power:

Let a be a certain number, n be a positive integer, and the n power of a is expressed as a? That represents the result of n times multiplication, such as 2? =2×2×2×2= 16。 The definition of power can also be extended to zero power, negative power, fractional power, irrational power and even imaginary power.

When m is a positive integer, n m represents n times of m in the formula. When m is a decimal, m can be written as a/b (where a and b are integers), n m means n a and b times the root sign.