Determine the angle of inclination

A. X+y+1=0
B.3-2y =9x

The angle of inclination is always between 0o and 180o and is measured CCW from the positive x-axis.

A. x+y+1 = 0
x+y = -1
Tan A = m = -A/B = -1/1 = -1
Ar = -45o = Reference angle.
A = -45 + 180 = 135o.

B. 3-2y = 9x
9x+2y = 3

Tan A = m = -A/B = -9/2 = -4.5
Ar = -77.47o
A = -77.47+180 = 102.5o