Question

Solve for x and y:x & y:x+y+yx​=21​ & (x+y)yx​=21​,x,y are real.


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Answer 1

Answer:

If x and y are positive integers and 1 + x + y +xy = 21, what is the value of x?

--> --> either and OR and . Notice that and OR and is not possible since in this case either or equals zero and we are told that and are positive integers.

Now, from and --> and AND from and --> and .

(1) y>3 --> , so . Sufficient.

(2) y=6 --> . Sufficient.

hope it helps