A new linear road is planned to be constructed perpendicular to an existing one. On a representative grid, a surveyor determines that the existing linear road passes through the points LaTeX: (4,7)( 4 , 7 ) and LaTeX: (2,15)( 2 , 15 ). The roads must intersect at the point LaTeX: (4,7)( 4 , 7 ).

(a) Determine the slope of the new road.

(b) Determine the equation of the new road.