=1/3-1/4+1/4-1/5+...+1/8-1/9
=1/3-1/9
=3/9-1/9=2/9
Tính nhanh B =(1/2x3 + 1/3x4 + 1/4x5 +1/5x6 +1/6x7+1/7x8 + 1/8x9 + .... + 1/50x51) + ( 5/6 + 19/ 20 + 41/42 + 71/72 + .... + 2549/2550 )
a)1,27+2,77+4,27+5,77+...+31,27+32,77
b)1/1x2+1/2x3+1/3x4+1/4x5+1/5x6+1/6x7+1/7x8 +1/8x9+1/9x10
mình cần gấp
\(\frac{1}{1x2}+\frac{1}{2x3}+\frac{1}{3x4}+\frac{1}{4x5}+\frac{1}{5x6}+\frac{1}{6x7}+\frac{1}{7x8}+\frac{1}{8x9}+\frac{1}{9x10}\)
Cho A=1/2x3+1/4x5+1/5x6+1/6x7+1/7x8+1/8x9+.....+1/98x99
Chứng minh rằng 1/5<A<2/5
2/2x3+2/3x4+2/4x5+2/5x6+2/6x7+2/7x8+2/8x9+2/9x10
các bạn giúp mình với nhé
Tính nhanh:
a.
\(\frac{16x18-6}{16x17+10}\)
b.
\(\frac{3}{3x4}+\frac{3}{4x5}+\frac{3}{5x6}+\frac{3}{6x7}+\frac{3}{7x8}+\frac{3}{8x9}\)
trình bày ra cho mình nhé!
a, \(\frac{1}{5x6}+\frac{1}{6x7}+\frac{1}{7x8}+\frac{1}{8x9}+\frac{1}{9x10}\)
b ,\(\frac{2}{10x12}+\frac{2}{12x14}+\frac{2}{14x16}+.........+\frac{2}{998x1000}\)
.c, \(\frac{4}{1x2}+\frac{4}{2x3}+\frac{4}{3x4}+........+\frac{4}{69x90}\)
Các bạn giúp mình nhé !
Tìm y, biết:
( y+ \(\frac{1}{2x3}\)) + ( y + \(\frac{1}{3x4}\)) +( y+\(\frac{1}{4x5}\)) + ( y +\(\frac{1}{5x6}\) ) + ( y + \(\frac{1}{6x7}\)) + ( y+ \(\frac{1}{7x8}\)) =\(\frac{29}{8}\)
Tính nhanh tổng sau :
1/1x2 + 1/2x3 + 1/3x4 + 1/4x5 + 1/5x6 + 1/6x7
ai nhanh mình tích cho mình cần gấp đó
\(A=\frac{5}{1x2}+\frac{5}{2x3}+\frac{5}{3x4}+\frac{5}{4x5}+\frac{5}{5x6}+\frac{5}{6x7}+\frac{5}{7x8}\)
Ai nhanh mk tick nha!
