\(\frac{4}{2x4}+\frac{4}{4x6}+\frac{4}{6x8}+\frac{4}{8x10}+...+\frac{4}{16x18}+\frac{4}{18x20.}\)
tính : a, 4/2x4+4/4x6+4/6x8+......+4/16x18+4/18x20
b, 1/2+1/6+1/12+1/20+......+1/90
\(\frac{4}{2x4}x\frac{4}{4x6}x\frac{4}{6x8}x.......x\frac{4}{16x18}x\frac{4}{18x20}\)
Tính :
N = ( 1/2x4 + 1/4x6 + 1/6x8 + 1/8x10 + ....... + 1/98 X 100 ) : ( 1/2 + 1/4 + 1/8 + 1/16 + ........ + 1/512 )
4/2x4+4/4x6+4/6x8+...+4/18 x20 = ?
Kết quả của phép tính : 1/2x4 + 1/4x6 + 1/6x8 + ......... + 1/96x98 + 1/98x100 là bao nhiêu ?
(1/2x4+1/4x6+1/6x8+1/8x10)xy=1/3
tìm y:
(2/2x4 + 2/4x6 + 2/6x8 + 2/8x10) x y = 1/3
(1phan 2x4+1 phan 4x6+1 phan 6x8+1phan 8x10)xy 1phan 3