Question

The product of Arun’s age,5 years ago with his age 9 years later is 15 then Arun’s present age is:
a) 6yrs
b) 8yrs
c) 10yrs
d) 12yrs​

Answer 1

The answer to your question is :

Let Arun's present age be x

(x-5)(x+9)=15

By using identity

x^2+(-5+9)x+ (-5×9)= 15

x^2+4x-45=15

x^2+4x-60=0

By splitting the middle term

x^2-6x+10x-60=0

x(x-6)+10(x-6)=0

(x+10)(x-6)=0

Therefore to make the equation zero

x+10=0 , x-6=0

x= (-10) , 6

Since age cannot be negative

Therefore Arun's present age is 6

Option (a) is correct