a) cho 20 so chan lien tiep biet rang so chung binh cong la 101 tim so lon nhat
b) tich 19 x 29 x 39 x ..... x ket qua co chu so tan cung la may
c) tinh tong cua 30 so le lien tiep tu 123 tro di . tong cua cac so do la
19 * 29 *39 * .... * 199 ket qua co chu so tan cung la may
khi thuc hien phep nhan 2 thua so, mot ban da viet nham 2 chu so cuoi cung cua thua so thu 1 la 35 thanh 53 nen co ket qua la 22197.tim 2 thua so da cho, biet rang tich dung cua chung la 21315
khong lam phep tinh ,hay cho biet ket qua cua moi phep tinh sau co tan bang chu so nao ?giai thich tai sao?
a.2*4*6*8...*96*98*5
b.5*15*25*...*2025
c.59*69*79*89-21*41*61*81
d.4*14*24*...*2024
Tich 19 x29 x39 x.......x199 co ket qua co chu so tan cung la :
Tim giup minh nhe ! Thanks
Khi cong mot so tu nhien co 4 chu so voi mot so tu nhien co 5 chu so,mot ban da dat tinh nham de cac chu so cua so co 4 chu so lech sang ben trai 1 hang va thang hang voi cac chu so cua so co 5 chu so.Vi vay ket qua thu duoc tang them 11106 don vi.Hoi:a.Tim ket qua dung cua phep cong biet so co 5 chu so la 12345.b.Tim so co 5 chu so do biet ket qua sai la 55550
Ket qua cua day tinh:1*2*3*4*5*6*7+64:8 co tan cung la chu so nao?
khi thuc hien mot phep nhan 2 so, mot ban hoc sinh viet nham chu so 4 o hang don vi cua mot thua sothanh chu so 1 ,vi the ban do da tim ra ket qua la 525.hay tim hai so da cho biet tich dung la 600