If 3x + 4y – k = 0 and 6x + 8y – 4 = 0 are coincident lines, then

1.	If 3x + 4y – k = 0 and 6x + 8y – 4 = 0 are coincident lines, then the value of k is ……………… A) 3 B) 4C) 6 D) 2
Answer» Correct option is (D) 2 For coincident lines, we have \(\frac{a_1}{a_2}=\frac{b_1}{b_2}=\frac{c_1}{c_2}\) \(\Rightarrow\) \(\frac36=\frac48=\frac{-k}{-4}\) \(\Rightarrow\) \(\frac k4=\frac12\) \(\Rightarrow\) \(k=\frac42=2\) Correct option is D) 2

If 3x + 4y – k = 0 and 6x + 8y – 4 = 0 are coincident lines, then the value of k is ……………… A) 3 B) 4C) 6 D) 2

Answer»

Correct option is (D) 2

For coincident lines, we have

\(\frac{a_1}{a_2}=\frac{b_1}{b_2}=\frac{c_1}{c_2}\)

\(\Rightarrow\) \(\frac36=\frac48=\frac{-k}{-4}\)

\(\Rightarrow\) \(\frac k4=\frac12\)

\(\Rightarrow\) \(k=\frac42=2\)

Correct option is D) 2