y+3/2x=7 (a)
9y-6x=27 (b)
Express both lines in slope-intercept form:
y= mx+b
Where :
m= slope
b= y-intercept
a.
y= -3/2x+7
m= -3/2
b.
9y-6x=27
9y= 6x+27
y= (6x+27)/9
y= 2/3x+3
m= 2/3
Both slopes are negative reciprocals of each other.
If two lines have negative reciprocal slopes, they are perpendicular lines.
PERPENDICULAR.