<a href="http://www.codecogs.com/eqnedit.php?latex=\frac{ax_{1} @plus; by_{1}@plus; c}{\sqrt{a^2@plus;b^2}} = 4 \\\\ \frac{3x_{1} @plus; 4y_{1} @plus; 5}{\sqrt{25}}= 4 \\\\ 3x @plus; 4y @plus; 5 = \pm 20 \\\\ 3x @plus; 4y @plus; 25 = 0~ and~ 3x @plus; 4y - 15 = 0" target="_blank"><img src="http://latex.codecogs.com/gif.latex?\frac{ax_{1} + by_{1}+ c}{\sqrt{a^2+b^2}} = 4 \\\\ \frac{3x_{1} + 4y_{1} + 5}{\sqrt{25}}= 4 \\\\ 3x + 4y + 5 = \pm 20 \\\\ 3x + 4y + 25 = 0~ and~ 3x + 4y - 15 = 0" title="\frac{ax_{1} + by_{1}+ c}{\sqrt{a^2+b^2}} = 4 \\\\ \frac{3x_{1} + 4y_{1} + 5}{\sqrt{25}}= 4 \\\\ 3x + 4y + 5 = \pm 20 \\\\ 3x + 4y + 25 = 0~ and~ 3x + 4y - 15 = 0" /></a>