Question

The sum of reciprocals of a childs age ( in year ) 3 years ago and 5 years from now is 1/3. Find his present age​

Answer 1

Answer:

let the present age be x

so

1/x-3 + 1/x+5 = 1/3

x+5 +x-3 / (x+5)(x-3) = 1/3

2x + 2/ x² - 3x + 5x - 15 = 1/3

6x + 6 = x² + 2x - 15

x² - 4x -21 = 0

x² - 7x + 3x -21 = 0

x(x - 7) +3(x - 7)

(x+3)(x-7) = 0

x = -3,+7

age cannot be negative so

the child's present age is 7 years

Answer 2

Answer:

Please refer the attachment dear