Question

15. The sum and the multiplication of
two numbers are 11 and 18
. gradually. Find the sum of their
inverse.
[SSC, 2009]​​

Answer 1

Explanation:

Hm......!!!.........

Answer 2

Answer:

Let two numbers be x and y then

x+y=11 》x=11-y eqn(i)

And x*y=18 eqn(ii)

Putting eqn (i) in eqn (ii)

(11-y)(y)=18

11y-y^2=18

-y^2+11y-18=0

Multiplying by -1 both sides we will get

y^2-11y+18=0

y^2-9y-2y+18=0

y(y-9)-2(y-9)=0

(y-2)(y-9)=0

y=2 or y=9

So x=11-y=9 or x=2

Taking x=9 and y=2

Sum of their inverse will be

1/9+1/2

=2+9/18=11/18

So sum of inverse of x and y is 11/18.