Question 1002361
If you put them both into slope-intercept form, you can see their relationship better...so from
6x+7y=42
7x=16+6y
we get
7y = -6x + 42
y = (-6/7)x + 6
and
6y = 7x - 16
y = (7/6)x - 8/3
Their slopes are negative reciprocals and the lines are thus perpendicular.