If `x=3\ a n d\ y=-1,` find the values of each of the using identity: `(x/7+y/3)((x^2)/(49)+(y^2)/9-(x y)/(21))`

If x=3\ a n d\ y=-1, find the values of each of the using identity: (3/x-x/3)((x^2)/9+9/(x^2)+1)

If x=3 and y=-1, find the values of each of the using identity: ((x)/(7)+(y)/(3))((x^(2))/(49)+(y^(2))/(9)-(xy)/(21))

If x=3\ a n d\ y=-1, find the values of each of the using identity: (x/4-y/3)\ ((x^2)/(16)+(x y)/(12)+(y^2)/9)

If x=3\ a n d\ y=-1, find the values of each of the using identity: (5/x+5x)((25)/(x^2)-25+25 x^2)

If x=3 and y=-1, find the values of each of the using identity: ((x)/(4)-(y)/(3))((x^(2))/(16)+(xy)/(12)+(y^(2))/(9))

If x=3 and y=-1, find the values of each of the using identity: ((3)/(x)-(x)/(3))((x^(2))/(9)+(9)/(x^(2))+1)

If x=3\ a n d\ y=-1, find the values of each of the using identity: (9y^2-4x^2)(81 y^4+36 x^2y^2+16 x^4)

If x=3 and y=-1, find the values of each of the using identity: ((5)/(x)+5x)((25)/(x^(2))-25+25x^(2))

If x=3 and y=-1, find the values of each of the using identity: (9y^(2)-4x^(2))(81y^(4)+36x^(2)y^(2)+16x^(4))

If x-y=7\ a n d\ x y=9, find the value of x^2+y^2