9+99+999+9999+99999+999999+....+99999999
Tính nhanh:
9+99+999+9999+...........+99999....9999(10 chữ số)
Giúp đi mik tick cho!
x = 9+99+999+...+999999......9{số 999999......9 có 100 chữ số 9}. tìm x
9+99+999+9999+99999+999999+9999999+99999999+999999999+9999999999 = ?
A = 9 + 99 + 999 + 9999 + ... + 999...9 }100 chữ số 9
9+99+999+9999+99999+999999+9999999+99999999+999999999+9999999999
tính nhanh
Tính giá trị biểu thức : S=9+99+999+9999+...+99999......99999
gồm 2017 chữ số 9
GIUP MK CAU NAY VS
a. Tim chu so a va so tu nhien x sao cho (12 +3x)2 = 1a96
b. Tinh gia tri bieu thuc : S= 9+99+999+9999+....+99..99(2017 so 9)
Tinh tong: a) 9 + 99 + 999 + ... + 999...999 ( co 10 c/s 9 )
b) Tim x, biet: 1/21 + 1/28 = 1/36 +... + 2/x(x+1) = 2 / 9