Tim ST1 .Biet rang viet them chu so 3 vao ben trai ST1 ta duoc ST2.Biet ST2 gap 7 lan ST1 ,ST1 co 2 chu so
tim so co ba chu so biet rang neu viet them chu so 1 vao ben phai so do thi ta duoc mot so gap 3 lan so co duoc bang cach viet them chu so 2 vao ben trai so do
cho 3 STN co tong la 130 . Tim 3 so do . Biet rang ST1 chia ST2 duoc 2 du 2 . ST2 chia ST3 duoc 3 du 2
(may tinh cu ko viet co dau duoc)
Lam nhanh ho nha
。丁ớ… 。…丫仓u… 。…。…吖’…。
Gọi ST3 là : x .
=> ST2 là : 3x - 2.
=> ST1 là : 2(3x - 2) + 2 hay 6x - 2.
=> Tổng 3 số đó là :
x + 3x - 2 + 6x - 2 = 10x - 4
=> 10x - 4 = 130 <=> 10x = 134
<=> x = 13,4
Vậy tương tự , ST1 = 78,4.
ST2 = 38,2.
ST3 = 13,4.
tim so co 4 chu so, biet rang khi viet them chu so 5vao ben phai so do ta duoc so lon gap 5 lan so nhan duoc khi ta viet them chu so 1 vao ben trai so do
tự tìm đi hỏi làm gì?
tim mot so co 3 chu so , biet rang khi viet them chu so 3 vao ben trai so do ta duoc mot so gap 5 lan so can tim
tim 1 so co 2 chu so biet rang neu viet them chu so 12 vao ben trai so do ta duoc 1 so gap 26 lan so can tim
goi so can tim la ab (a khac 0, a,b >10)
so mới là: 12ab
ta có: ab*26=12ab
ab*26=1200+ab
ab*26-ab=1200
ab*(26-1)=1200
ab*25=1200
ab=48
vay so can tim la 48
Tim mot so tu nhien co 5 chu so , biet rang neu viet them 2 chu so vao ben phai so do thi duoc so lon gap 3 lan so viet them chu so 2 vao ben trai so do .
tim 1 so co 2 chu so biet rang neu viet them vao ben trai ben phai so do 1 chu so 5 ta duoc 1 so moi co 4 chu so gap 75 lan so phai tim
Tìm so co hai chu so biet rang neu ta viet them chu so 2 vao ben trai va ben phai so do ta duoc so moi gap 36 lan so phai tim.
mot so tu nhien co 5 chu so. biet rang viet them 1 vao ben phai va them chu so1 vao ben trai thi ta duoc so moi lon gap 3 lan so ban dau. tim so ban dau