Giải thích các bước giải:
`(1-1/2^2)(1-1/3^2)(1-1/4^2)...(1-1/x^2)=1007/2012`
`=>1.3/2^2. 2.4/3^2 . 3.5/4^2 ... ((x-1)(x+1))/x^2=1007/2012`
`=>(1.2.3...(x-1))/(2.3.4...x).(3.4.5...(x+1))/(2.3.4...x)=1007/2012`
`=>1/x . (x+1)/2 =1007/2012`
`=>(x+1)/(2x) =1007/2012`
`=>1007.2x=2012(x+1)`
`=>2014x=2012x+2012`
`=>2014x-2012x=2012`
`=>2x=2012`
`=>x=1006`