※ 引述《tokyo291 (工口工口)》之銘言：
: 62/(a+b)+152/(a+3b)+242/(a+5b)=27
: 62/(a+b)+3*152/(a+3b)+5*242/(a+5b)=81
: 請問這種形式有甚麼方式比較好解嗎?
: 我通分完之後一直卡在次方太高無法消掉...
62/(a+b)+ 152/(a+3b)+ 242/(a+5b) = 27...(1)
62/(a+b)+3*152/(a+3b)+5*242/(a+5b) = 81...(2)
(2)-(1) = 2*152/(a+3b)+4*242/(a+5b) = 54...(3)
(3)/2 = 152/(a+3b)+2*242/(a+5b) = 27...(4)
(1)=(4) => 62/(a+b) = 242/(a+5b) => 31/(a+b) = 121/(a+5b)
=> 121a+121b = 31a+155b
=> 90a = 34b => a = 34b/90
=> 62/(124b/90) + 152/(304b/90) + 242/(484b/90) = 27
=> 45/b + 45/b + 45/b = 27
=> 135/b = 27 => b = 135/27 = 5 => a = 34*5/90 = 17/9
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