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प्रश्न
The sum of reciprocals of Meena’s ages (in years ) 3 years ago and 5 years hence `1/3` Find her present ages.
उत्तर
Let the present age of Meena be x years
Meena’s age 3 years ago =(x-3)years
Meena’s age 5 years hence =(x+5) years
According to the given condition,
`1/(x-3)+1/(x+5)=1/3`
⇒`(x+5+x-3)/((x-3)(x+5))=1/3`
⇒`(2x+2)/(x^2+2x-15)=1/3`
⇒`x^2+2x-15=6x+6`
⇒`x^2-4x-21=0`
⇒`x^2-7x+3x-21=0`
⇒`x(x-7)+3(x-7)=0`
⇒`(x-7)(x+3)=0`
⇒`x-7=0 or x+3=0`
⇒`x=7 or x=-3`
∴` x=7 ` (Age cannot be negative)
Hence, the present age of Meena is 7 years.
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