So y=mx+b is still prevalent here even if it's an inequality. Meaning your slope AND y-intercept can help you. Even if it's in ax+by=c you can easily get the y alone into slope-intercept.
y<_3x+5 for example. For one, it is y is less than or equal to 3x+5. So the line shouldn't be dotted. So that leaves us with the two far-right graphs to look at. 5 is our y-intercept in the equation. So look at our graph and see which one has the line passing through 5. They both do. Okay, well we can still use our sign, it shows that y is LESS than 3x+5. So the shaded blue part should be on the right. If it was the other way around it would be the left. So our graph should be the far right for this equation.
Hope this helps... I know it's kind of messy. If you need any more help let me know. But I hope I outlined what to look for.