The number of pairs (x,y) which will satisfy the equation `x^2-x y+y^2=4(x+y-4)` is

The number of pairs (x,y) which will satisfy the equation x^(2)-xy+y^(2)=4(x+y-4) is

The number of integral pairs (x, y) satisfying the equation 2x^(2)-3xy-2y^(2)=7 is :

The number of pairs (x, y) where x,y are integers satisfying the equation 21x + 48y = 5 is

The number of positive integral pairs (x, y) satisfying the equation x^(2) - y^(2) = 3370 is :

The number of positive integral pairs (x, y) satisfying the equation x^(2) - y^(2) = 3370 is :

The number of ordered pairs of integers (x,y) satisfying the equation x ^2+6x+y^2 =4 is

The number of ordered pair (x, y) satisfying the equation sin^(2) (x+y)+cos^(2) (x-y)=1 which lie on the circle x^(2)+y^(2)=pi^(2) is _________.

The number of ordered pair (x, y) satisfying the equation sin^(2) (x+y)+cos^(2) (x-y)=1 which lie on the circle x^(2)+y^(2)=pi^(2) is _________.