"3x + 2y = –11 written in slope-intercept form is y = x." Not so.
To find the slope of this line, solve for y:
2y = -3x - 11 => y = (-3/2)x - 11/2. The slope of the given line is -3/2. The
graph of the new (perpendicular) line will then be the negative reciprocal of -3/2, or +2/3.
Now use the point-slope formula for the equation of a straight line to determine the equation of this new (perpendicular) line thru (-6,5):
y-5 = (2/3)(x+6) (answer)