3/1+3/1+2 3/1+2+3+3/1+2+3+4+3/1+2+3+4+5+....+3/1+2+3+4..+99
1/1*2 +1/2*3 +1/3*4 + 1/4*5 +...+1/n*(n+1) 3/1*2+3/2*3+3/3*4+3/4*5+...+3/n*(n+1) tính tổng nha các bạn
tính nhanh
a (1-1/2) x (1-1/3) x (1-1/4) x (1-1/5)
b (1-3/4)x ( 1-3/7) x ( 1-3/10) x (1-3/13) x...x (1-3/97) x (1-3/100)
(1-3/4)*(1-3/7)*(1-3/10)*(1-3/13)*........*(1-3/97)*(1-3/100)
1-3/4*1-3/7*1-3/10*1-3/13*............*1-3/97*1-3/100
a) (1-1/2).(1-1/3).(1-1/4).(1-1/5)
b) (1-3/4).(1-3/7).(1-3/10). ..... .(1-3/97).(1-3/100)
tính nhanh
BÀI TÍNH NHANH
A.2/3+2/6+2/12+2/24+2/48+2/96+2/192
B.1/2+1/4+1/8+1/16+1/32+1/64+1/128+1/256
C.1/3+1/9+1/27+1/81+1/243+1/729
D.3/2+3/8+3/32+3/128+3/512
E.3+3/5+3/25+3/125+3/625
A=5/1x6+5/6x11+5/11x16+5/16x21+...+5/101x106
B=3/1x4+3/4x7+3/7x10+....+3/97x100
C=1/2x7+1/7x12+1/12x17+....+1/97x102
D=1/2+1/6+1/12+1/20+1/30+1/42+1/56+1/72
E=3/2x4+3/4x6+3/6x8+....+3/98x100
A=(1 - 1/1+2) x (1-1/1+2+3) x (1-1/1+2+3) x (1-1/1+2+3)x1-1/1+2+3+4)x ... x (1-1/1+2+3+...+2018)
bài 1:
a) y2 1/3 = 1 3/4:2 1/3
b) 2/3 + 3/4 : 6/7 + 1/8 x 1 1/3
c)5 2/3 - 1 3/4 x 2 2/3