If x and y are integers such that x^2= y and xy = 343, then x – y = ?  Answers: A) -42 B) -20 C) -5 D) 5 E) 20
here x and y are integers .   x^2=y,xy =343.   substitute x^2=y in xy =&gt; x^3=343.   here x^3 is positive ,   x is also positive.   x=7 then y=49.   x-y=-42   so option -42 is correct
<result>A</result>
If x and y are integers such that x^2= y and xy = 343, then x – y = ?