Find a plane containing the point (4, 4, 8) and the line of intersection of the planes 6x + 7y + 7z = 41 and - 3x - y + 7z = 0
well, the line of intersection is
(x - 41/9) / (8/9) = y/-1 = (z - 41/21) / (5/21)
Now, do you recall how to find the plane given a point and a line?