Answer:
The lines are perpendicular.
Step-by-step explanation:
One way to find out is to put both equations in the y intercept form:
y = mx + b
The first one:
9 + 4x = 9y
9y = 4x + 9
y = 4/9x + 9/4
So the slope is 4/9.
The second one:
9x + 4y = 7
4y = -9x + 7
y = -9/4x + 7/4
The slope is -9/4.
The slope of a perpendicular line is the negative reciprocal.
