灵饰物爆好还是狂暴好:一道数学问题~要列式啊!!

来源:百度文库 编辑:杭州交通信息网 时间:2024/03/29 06:19:30
在下面的式子中,最大的得数是 几 ???
(1)(1/17+1/19)*20 (2)(1/24+1/29)*30
(3)(1/31+1/37)*40 (4)(1/41+1/47)*50

要算的过程!

(1/31+1/37)*40=(2/31+2/37)*20>(1/17+1/19)*20
(1/31+1/37)*40=(4/93+4/111)*30>(4/96+4/116)*30
=(1/24+1/29)*30
(1/31+1/37)*40=(4/155+4/185)*50>(4/164+4/188)*50
=(1/41+1/47)*50
(1/31+1/37)*40最大
另一种解法;
(1/17+1/19)*20=(1/510+1/570)*600
(1/31+1/37)*40=(1/465+1/555)*600
(1/24+1/29)*30=(1/480+1/580)*600
(1/41+1/47)*50=(1/492+1/564)*600
1/465>1/480>1/492>1/510
1/555>1/564>1/570>1/580
(1/31+1/37)*40>(1/24+1/29)*30
(1/31+1/37)*40>(1/17+1/19)*20
(1/31+1/37)*40>(1/41+1/47)*50
(1/31+1/37)*40最大

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