Question

[Khởi My Công Chúa]

\(\text{s}o\)\(\text{s}nh\)

\(32^{81}\)với \(31^{90}\)

\(1102^{2009}-1102^{2008}\)với\(1102^{2008}-1102^{2007}\)

Answer 1

[Quang Phan Minh]

32⁸¹=2⁴⁰⁵=2^{9^45}

31⁹⁰=31^{2^45}

mà 2⁹<31² (512<961)

suy ra 32⁸¹<31⁹⁰

Answer 2

[Quang Phan Minh]

gọi a=1102²⁰⁰⁷

có: a.1102²-a.1102=a.(1102²-1102)

      a.1102-a=a.1101

mà 1102²-1102>1101

=> a.1102²-a.1102>a.1102-a

vậy 1102²⁰⁰⁹-1102²⁰⁰⁸>1102²⁰⁰⁸-1102²⁰⁰⁷