Full explanation and process

a)xty =4 b) xty=2 c)x- y=4 d) xty = - 4 6. Which function has removable discontinuity? a) f (x ) = X x+1 b ) f (x ) = *' - 1 c) f(x) = tan x d) f(x) = x for x > 0 x+1 x +1 for x