Find an equation for the plane (a) through the point (0, 2, 5) perpendicular to 6i+j-k (b) through the origin perpendicular to (-1,-1) (c) through the origin perpendicular to the segment from (3, 8, 7) to (4, 1,-9) (d) through the point (3, 2, 3) parallel to the plane with equation 7x + 3y +z = 8 (e) through the point (2, -7,7) perpendicular to the line with parametric equa- tions x = =7t+1, y = -6t+7, and z = 3