The plane denoted by P1:4x+7y+4z+81=0 is rotated through a right angle about its line of intersection with the plane P2:5x+3y+10z=25. If the plane in its new position is denoted by P, and the distance of this plane from the origin is k, then the value of [k2] is (where [.] represents greatest integer less than or equal to k).

The plane denoted by P1:4x+7y+4z+81=0 is rotated through a right angle

1.	The plane denoted by P1:4x+7y+4z+81=0 is rotated through a right angle about its line of intersection with the plane P2:5x+3y+10z=25. If the plane in its new position is denoted by P, and the distance of this plane from the origin is k, then the value of [k2] is (where [.] represents greatest integer less than or equal to k).
Answer» The plane denoted by $P_{1} : 4 x + 7 y + 4 z + 81 = 0$ is rotated through a right angle about its line of intersection with the plane $P_{2} : 5 x + 3 y + 10 z = 25$ . If the plane in its new position is denoted by $P$ , and the distance of this plane from the origin is $k$ , then the value of $[\frac{k}{2}]$ is (where [.] represents greatest integer less than or equal to $k$ ).