Toán Cho A = 1/7 + 2/16 + 3/41 + 4/97 + 5/205. Chứng tỏ rằng A < 15/34 16/08/2021 By aikhanh Cho A = 1/7 + 2/16 + 3/41 + 4/97 + 5/205. Chứng tỏ rằng A < 15/34
Giải thích các bước giải: A<5/35+1/8+3/41+4/96+1/41 =5/35+1/8+3/41+1/24+1/41 =5/35+3/24+1/24+3/41+1/41 =5/35+4/24+4/41 =5/35+1/6+4/41 =5/35+6/36+4/41 Ta có: 5/35<5/34 ; 6/36<6/34 ; 4/41<4/34 =>5/35+6/36+4/41<5/34+6/34+4/34=15/34 Vậy: 1/7+2/16+3/41+4/7+5/205<15/34 Trả lời
Giải thích các bước giải:
A<5/35+1/8+3/41+4/96+1/41
=5/35+1/8+3/41+1/24+1/41
=5/35+3/24+1/24+3/41+1/41
=5/35+4/24+4/41
=5/35+1/6+4/41
=5/35+6/36+4/41
Ta có: 5/35<5/34 ; 6/36<6/34 ; 4/41<4/34
=>5/35+6/36+4/41<5/34+6/34+4/34=15/34
Vậy: 1/7+2/16+3/41+4/7+5/205<15/34