It is known that LXL is less than or equal to 1 and Lyl is less than or equal to 1. Let m = LX + YL + ly + 1L + l2y-x-4l, find the maximum and minimum of M

It is known that LXL is less than or equal to 1 and Lyl is less than or equal to 1. Let m = LX + YL + ly + 1L + l2y-x-4l, find the maximum and minimum of M

Because | x | = - 1, then x + 1 > = 0;
Again|