Give the slope intercept form of the equation of the line that is perpendicular to 5x-3y=8

Hello : 
let the slope : a    and ; b the slope of the line : 5x - 3y = 8
the line that is perpendicular to 5x-3y=8  so : a×b = - 1 
but : 
5x - 3y = 8...      y = (5/3)x - 8/3  when : b = 5/3
 the slope intercept form of the equation of the line that is perpendicular
 to 5x-3y=8 is : y = (5/3)x +c 

The answer is 76° i believe