What is not perpendicular to 7x +2y= 3

Every line that does not have the slope of 2/7 is perpendicular to this line.

In order to find this fact, we first must find what is perpendicular. To do that, we first have to find the slope of this line. We can do this by solving for y.

7x + 2y = 3

2y = -7x + 3

y = -7/2x + 3/2

Now we can take the slope of -7/2 and flip and negate it. This will give us the perpendicular slope (2/7). Now we know any line that does not have this slope is not perpendicular to this line.