Question

In 11 years, the age of Russel will be half of the square of the age he was 13 years ago. Find his present age.

Answer 1

x + 11 = ( 1 / 2 ) ( x - 13 ) ^ 2

x + 11 = ( 1 / 2 ) ( x ^ 2 - 2 x *13 + 13 ^ 2 )

x + 11 = ( 1 / 2 ) ( x ^ 2 - 26 x + 169 )

1 / 2 ( x ^ 2 ) - 13 x - x + 169 / 2 - 11 = 0

( 1 / 2 ) x ^ 2 - 13 x - x + 169 / 2 - 22 / 2 = 0


( 1 / 2 ) x ^ 2 - 13 x - x + 147 / 2 = 0


The exact solutions are:

7

or

21

Answer 2

In 11 years, the age of Russel will be half of the square of the age he was 13 YEARS AGO.

For that reason present age = 21