`(2/(2xx4)+2/(4xx6)+2/(6xx8)+2/(8xx10))xxy=1/3`
`=>(1/2-1/4+1/4-1/6+1/6-1/8+1/8-1/10)xxy=1/3`
`=>(1/2-1/10)xxy=1/3`
`=>(5/10-1/10)xxy=1/3`
`=>4/10xxy=1/3`
`=>2/5xxy=1/3`
`=>y=1/3:2/5`
`=>y=1/3xx5/2`
`=>y=5/6`
`(2/(2xx4)+2/(4xx6)+2/(6xx8)+2/(8xx10))xxy=1/3`
`=>(1/2-1/4+1/4-1/6+1/6-1/8+1/8-1/10)xxy=1/3`
`=>(1/2-1/10)xxy=1/3`
`=>(5/10-1/10)xxy=1/3`
`=>4/10xxy=1/3`
`=>2/5xxy=1/3`
`=>y=1/3:2/5`
`=>y=1/3xx5/2`
`=>y=5/6`
tìm y :( 1/2x4 + 1/4x6 + 1/6x8 + 1/8x10 ) x y = 1/3
sos cố gắng giúp mik vs . mình cảm ơn
Bài 1 tìm y
a) (1/2x4+1/4x6+1/6x8+1/8x10)x y =1/3
b) y:8+y x8-56,78=69,11x2
Tìm y biết \(\left(\frac{1}{2x4}+\frac{1}{4x6}+\frac{1}{6x8}+\frac{1}{8x10}\right).y=\frac{1}{3}\)
Tính :
N = ( 1/2x4 + 1/4x6 + 1/6x8 + 1/8x10 + ....... + 1/98 X 100 ) : ( 1/2 + 1/4 + 1/8 + 1/16 + ........ + 1/512 )
(1/2x4+1/4x6+1/6x8+1/8x10)xy=1/3
(1phan 2x4+1 phan 4x6+1 phan 6x8+1phan 8x10)xy 1phan 3
tính nhanh
\(\frac{2}{2x4}\) + \(\frac{2}{4x6}\) + \(\frac{2}{6x8}\) +\(\frac{2}{8x10}\)
3/4x6+3/6x8+3/8x10+.............+3/nx(n+2)=9/25
\(\frac{4}{2x4}+\frac{4}{4x6}+\frac{4}{6x8}+\frac{4}{8x10}+...+\frac{4}{16x18}+\frac{4}{18x20.}\)