If the normal to the curve $y ( x ) = \int _ { 0 } ^ { x } \left( 2 t ^ { 2 } - 15 t + 10 \right) d t$ at a point $( a , b )$ is parallel to the line $x + 3 y = - 5 , a > 1$, then the value of $| a + 6 b |$ is equal to $\_\_\_\_$.
If the normal to the curve $y ( x ) = \int _ { 0 } ^ { x } \left( 2 t ^ { 2 } - 15 t + 10 \right) d t$ at a point $( a , b )$ is parallel to the line $x + 3 y = - 5 , a > 1$, then the value of $| a + 6 b |$ is equal to $\_\_\_\_$.