1/72+ 1/90 + 1/ 110 + .....+1/9702+1/9900
= 1/ 8x9 + 1/9x10+1/10x11+.....+1/98x99+1/99x100
.....
= 1/8 - 1/100
=23/200
1/72+ 1/90 + 1/ 110 + .....+1/9702+1/9900
= 1/ 8x9 + 1/9x10+1/10x11+.....+1/98x99+1/99x100
.....
= 1/8 - 1/100
=23/200
Tính nhanh . a) 1/90 + 1/72+ 1/ 110 + .....+1/9702+1/9900
tính nhanh
1/20+1/30+1/42+1/56+1/72+1/90+1/110+1/132
Tính nhanh:
1/20 + 1/30 + 1/42 + 1/56 + 1/72 + 1/90 + 1/110 + 1/132
Tính nhanh:
A= 1/110+ 1/90+ 1/72+ 1/56+......+1/2.
Ghi cả cách làm nhé!!!
Tính nhanh
\(\dfrac{1}{20}\)+\(\dfrac{1}{30}\)+\(\dfrac{1}{42}\)+\(\dfrac{1}{56}\)+\(\dfrac{1}{72}\)+\(\dfrac{1}{90}\)+\(\dfrac{1}{110}\)+\(\dfrac{1}{132}\)
=
Tính nhanh 1/2 + 1/6 + 1/12+ 1/20 + 1/30 + 1/42 + 1/56 + 1/72 + 1/90 + 1/110 = .....
tinh nhanh 1/110 cong 1/90 cong 1/72 cong 1/56 .Giai giup toi voi
T = 1/2 +1/6 +1/12 + 1/20 + 1/30 + ... + 1/9702 + 1/9900
Hãy tính T = tổng các bn nhé !
tinh nhanh
A=1/110+1/90+1/72+1/86+....+1/2
ghi ca loi giai nhe !