In the equation Y = MX + C, M is the slope, so you can rearrange your equation to read the same way.

3X + 4Y = 1

4Y = -3X + 1

Y = (-3X)/4 + 1/4

Now this is in the form Y = MX + C, where M = -3

So your slope is -3

I hope this helps

3X + 4Y = 1

4Y = -3X + 1

Y = (-3X)/4 + 1/4

Now this is in the form Y = MX + C, where M = -3

So your slope is -3

I hope this helps