Re: [中學代數一題.....

[ttinff (mmmm)]

※ 引述《adamchi (adamchi)》之銘言：
: 設n為正整數,且滿足 25n^2+24n+34 等於相鄰兩個正整數的乘積
: 則n=_____
: 麻煩大家~~
        (5n+3)^2 = 25n^2 +30n+ 9
        (5n+2)^2 = 25n^2 +20n+ 4
      => 25n^2 + 24n +34 = (5n+2)(5n+3)
                         = 25n^2 +25n +6
      => n= 28


--
※ 發信站: 批踢踢實業坊(ptt.cc) 
◆ From: 61.227.193.132
推 jeff413     :2也可以
推 a016258     :(5n+m)(5n+m+1) ， m=0.1.2.3.4
推 jeff413     :應該只要看2.3.4就可以了
推 tsaifc      :17898
→ ttinff      :拍謝~欠考慮...XD