gọi số cần tìm là abc.theo bài ra ta có:
abc5=1580+abc
=>10.abc+5=1580+abc
=>10.abc-abc=1580-5
=>9.abc=1575
=>abc=175
Vậy số cần tìm là 175
tim 1 so biet rang neu viet them vao ben phai so do 1 so co 2 chu so thi duoc so moi lon hon so phai tim la 197406
Tim so tu nhien co 2 chu so biet neu viet them chu so 1 vao ben phai so do ta duoc tong so moi va so do la 980 .
Tim mot so biet rang neu them vao ben phai so do 1so co 2 chu so ta duoc mot so lon hon so phai tim 19204
tim 1 so co 2 chu so .biet rang neu viet them vao ben trai so do thi duoc so moi nho hon 8 lan so ban dau la 22 don vi
1.Cho so N la so co hai chu so chia het cho 3.Neu viet xen so 0 vao giua hai chu so do roi cong no voi hai lan chu so hang chuc cua so N ta duoc so moi gap 9 lan so N.Tim so do
2.Tong hai so thap phan la 60,1.Neu dich dau phay cua so nho sang ben phai mot hang roi dem tru di so lon thi ta duoc 219,52.Tim hai so do.
3.Tim so co hai chu so biet neu ta them so 33 vao giua hai chu so do thi duoc mot so moi gap so phai tim 89 lan.
tim mot so tu nhien co 2 chu so biet rang neu viet them chu so 1 vao ben trai va ben phai so do thi duoc so co 4 chu so,lon gap 32 lan so da cho
cho mot so tu nhien neu viet them mot chu so vao ben phai so do thi so moi hon so cu dung 2013 don vi tim so da cho va so viet them
tim mot so tu nhien co 2 chu so biet rang neu viet vao ben trai so do mot chu so 6 thi duoc so moi gap 41 lan so phai tim
tim so co hai chu so biet rang neu ta viet them chu so 1 vao giua hai chu so cua so do ta duoc so moi gap so 9 lan so phai tim.tim so phai tim
