The distance between the straight lines $2 x+y+4=0$ and $2 x+y+8=0$ is

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Professor PC Thomas Classes · Answer

Distance between parallel lines $Ax+By+C_1=0$ and $Ax+By+C_2=0$ is $\frac{|C_1-C_2|}{\sqrt{A^2+B^2}} = \frac{4}{\sqrt{5}}$.