tim x
x:2+x:4x6+x:2x4
X:2+X:4x6+X:2x4=8
Xx0,5+Xx0,25x6+Xx0,5x4=8
Xx0,5+Xx1,5+Xx2=8
Xx(0,5+1,5+2)=8
Xx4 =8
X =8:4
X =2
1/2x4+1/4x6+…+1/(2x-2)x 2x=3/16 (x thuộc N , x lớn hơn hoặc bằng 2) Cíu mình zứi
tìm y:
(2/2x4 + 2/4x6 + 2/6x8 + 2/8x10) x y = 1/3
`(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`
giúp tính \(\dfrac{2}{2x4}+\dfrac{2}{4x6}x...x\dfrac{2}{2014x2016}\)
Nguyễn Huy Tú soyeon_Tiểubàng giải Akai Haruma
(1+1/1x3)x(1+1/2x4)x(1+1/3x5)x(1+1/4x6)x(1+1/5x7)
\(\frac{4}{2x4}x\frac{4}{4x6}x\frac{4}{6x8}x.......x\frac{4}{16x18}x\frac{4}{18x20}\)
ax4=1/2-1/4+1/4-1/6+1/6+1/8+.......+1/16-1/18+1/18+1/20
ax4 =1/2-1/20
ax4 =9/20
a=9/20:4
a=9/80
hãy tính kết quả bằng cách hợp lý
1/2x4 x 1/4x6 x 1/6x8 x .......................... x 1/100x112 x 1/112x114
theo công thức 1/n x 1 = 1/n - 1/1 mà làm
Tính và rút gọn kết quả thành PSTG
4/3x1 x 9/2x4 x 16/3x5 x 25/4x6
43𝑥1⋅92⋅𝑥4𝑥163⋅𝑥5⋅254⋅𝑥6
12𝑥12⋅𝑥4𝑥163⋅𝑥5⋅254⋅𝑥6
chúc bạn học tốt
4/3x1x9/2x4x16/3x5x25/4x6=172800/144=1200/1
tk nha
tìm x biết ( 1/2x4 + 1/4x6 + 1/6x8 ...+ 1/18x20) x 10 - \(x\) = 0
\(\left(\frac{1}{2.4}+\frac{1}{4.6}+\frac{1}{6.8}+...+\frac{1}{18.20}\right).10-x=0\)
\(2\left(\frac{2}{2.4}+\frac{2}{4.6}+\frac{2}{6.8}+...+\frac{2}{18.20}\right).10-x=0\)
\(2\left(\frac{1}{2}-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+\frac{1}{6}-\frac{1}{8}+...+\frac{1}{18}-\frac{1}{20}\right).10-x=0\)
\(2\left(\frac{1}{2}-\frac{1}{20}\right).10-x=0\)
\(2.\frac{9}{20}.10-x=0\)
\(9-x=0\)
\(x=9-0\)
\(x=9\)