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यद‌ि `x^(2)+1/(x^(2))=66` है तो `(x^(2)-1+2x)/x=?`A. `+-8`B. `10,-6`C. `6,-10`D. `+-4`

Answer» Correct Answer - B
`x^(2)+1/(x^(2))=66`
`implies x^(2)+1/(x^(2))-2=66-2`
`(x-1/x)^(2)=64`
`(x-1/x)^(2)=(8)^(2)`
`implies x-1/x=+-8`
`implies (x^(2)-1+2x)/x=((x^(2))/x-1/x+(2x)/x)/(x/x)`
`implies (x-1/x+2)/1`
When `x-1/x=+8`
Then `(x-1/x)+2=8+2=10`
When `x-1/x=-8`
`-8+2=-6`
`:. (10,-6)`


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