Question

已知P=99^9/9^99,Q=11^9/9^90,试比较p,Q的大小.

Answer 1

P=99^9/9^99,Q=11^9/9^90

P/Q=(99^9/9^99）/(11^9/9^90)

=（99^9*9^90)/(11^9*9^99)

=(99^9/11^9)*(9^90/9^99)

=(99/11)^9* 9^(90-99)

=9^9*9^(-9)

=1

所以P=Q