Question
What is the k value, if the straight lines ( k+2 y+3=0 ) and ( 8 x+k y-1=0 ) are parallel

What is the k value, if the straight lines ( k+2 y+3=0 ) and ( 8 x+k y-1=0 ) are parallel
(a) 2
(b) -4
(c) 4
Solution

( m_{1}=-frac{k}{2} )
( m_{2}=-frac{8}{k} )
Since the two his are parallel ( left(m_{1}=m_{2}right) )
[
begin{array}{l}-frac{k}{2}=-frac{8}{k} Rightarrow k^{2}=16end{array}
]
( k=pm 4 )