CMR: A= 1/2-2/2^2+3/2^3-4/2^4+....+99/2^99-100/2^100<2/9
CMR A=1/2-2/2^2+3/2^3-4/2^4+...+99/2^99-100/2^100<2/9
CMR 1/3-2/3^2+3/3^3-4/3^4+..........+99/3^99-100/3^100<3/4
Giúp mình với. Mình đang gấp
mình có bài toán mình chưa hiểu
mong moi người giúp đỡ
1+(1+2)+(1+2+3)+(1+2+3+4)+...+(1+2+3+4+...100)/100*1+99*2+99*3+...+3*98+2*99+1*100
CMR
1/2-2/2^2+3/2^3-4/2^4+.....+99/2^99-100/2^100<2/9
CMR: 1/2-2/2^2+3/2^3-4/2^4+.....99/2^99-100/2^100<2/9
Tính tổng :
a) 1+(-2)+3(-4)+...+19+(-20)
b) 1-2+3-4+...+99-100
c) 2-4+6-8+...+48-50
d) -1+3-5+7-..+97-99
e) 1+2-3-4+...+97+98-99-100
GIÚP MÌNH NHÉ MÌNH ĐANG CẦN GẤP ^-^
CMR:
a)1/2-1/4+1/8-1/16+1/32-1/64<1/3
b)1/3 - 2/3^2 + 3/3^3 - 4/3^4 +...+ 99/3^99 -100/3^100 < 3/16
cmr
a) 1/2 -1/4+1/8-1/16+1/32-1/64 <1/3
b) 1/3-2/3^2+3/3^3-4/3^4+...+99/3^99-100/3^100<3/16