Let the plane \( x + 3y - 2z + 6 = 0 \) meet the co-ordinate axes at the points \( A, B, C \). If the orthocenter of the triangle \( ABC \) is \( \left(\alpha, \beta, \dfrac{6}{7}\right) \), then \( 98(\alpha+\beta)^2 \) is equal to____.
