tìm y ( 1/1x3 + 1/3x5 + 1/5x7 + 1/7x9 + 1/9x11 ) x y= 2/3
tìm y biết :
(1/1x3 + 1/3x5 + 1/5x7 + 1/7x9 + 1/9x11 ) x Y =2/3
1/3x5+1/5x7+1/7x9...........1/17x19+1/x(x-2)
x=1/3x5+1/5x7+1/7x9+...+1/197+199
(1/3x5+1/5x7+1/7x9+.....+1/19x21)*x=9/7
Câu 1:
1/3x5 + 1/5x7 + 1/7x9 +......+ 1/997x999
1/1x3+1/3X5+1/5X7+1/7X9+…+1/99X101
1/3x5+1/5x7+1/7x9+.........+1/2n-1x2n-2
1/1x3 + 1/3x5 + 1/5x7 + 1/7x9 + 1/9x11