For perpendicular lines, the slopes of the two lines must be negative inverses. That means when we multiply the slopes, the product is -1.
To check this, we transform the two lines into slope-intercept form.
First line:
3 + 7x =8y
(we divide by 8 both sides)
y = (7/8)x + (3/8).
Slope is 7/8.
Second line:
We need to subtract (8x) from both sides and divide by 7.
8x+7y=9;
7y = 9-8x;
y = (-8/7)x + 9/7.
Can you finish the problem now?
