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 )