1/2 + 1/3 + 1/4 + 1/5 + 100
= 30/60 + 20/60 + 15/60 + 12/60 + 100
= 77/60 +100
= 385/300 + 300/300
= 685/300
= 137/100
1/2 + 1/3 + 1/4 + 1/5 + 100
= 30/60 + 20/60 + 15/60 + 12/60 + 100
= 77/60 +100
= 385/300 + 300/300
= 685/300
= 137/100
a. 1 + 2 + 4 + 8 + 16 +…+ 512
b. 1 + 3 + 9 + 27 + 81+… +729
6h mik đi học ùi giúp iii
1+1+2+2+3+3+4+4+5+5+.........+100+100
Tính nhanh
tính nhanh (2/3+3/4+5/6+...+99/100).(1/2+2/3+3/4+...+98/99)-(1/2+1/3+...+99/100).(2/3+2/4+...+98/99)
Tính
a) (x-1/2)+(x-1/4)+(x-1/8)+...+(x-1/512)
Tìm x
a) (x-1/1×2)+(x-1/2×3)+...+(x-1/100×101)
b) (x-1)+(x-2)+(x-3)+...+(x-101)=5050
c) x+1/2+1/3+1/4+...+1/100=3/2+4/3+5/4++...+101/100
tính nhanh
a,(1-1/10)+(1-1/11)+(1-1/12)+...+(1-1/99)+(1-1/100)
b,1/2*3+1/2*4+1/4*5+...+1/99*100
Tính tổng:a) S = 1 + 1 3 + 1 9 + 1 27 + 1 81 + 1 243 + 1 279
Tính nhanh
A=5+5/1+2+5/1+2+3+5/1+2+3+4+.......+5/1+2+3+........+100
Tính nhanh : ( 1 -1/2 ) × ( 1 - 1/3 ) × ( 1 - 1/4) × ( 1 - 1/5) × …….. × ( 1 - 1/99) × ( 1 - 1/100)
tính tổng
1+2+3+...+100
1+3+5+...+99+101
1+4+7+...+97+100