Consider I.yvonne12 wrote:If x+y are greater than 0, is X=1?
I. x/y =1
II. xy=1
why do we need both if 1(1) can only be 1 and its not a matter of signs, since it is stated along with the question.
x/y=1
=> x=y
x+y is positive will mean both x and y are positive and equal
But That is not sufficient to tell What X is
Consider II.
x=1/y
x+y is positive
=> both x,y are positive and y is the resiprocal of x
again not sufficient to tell what x is
Now if u combine I. and II.
x^2=1 and x is positive
which will give you the value of x as 1
which is sufficient
