Question

If 2 X + 3 y + 5 = 0,Kx+ 6y + 7 = 20 are parallel then the value of k is

Answer 1

2X+3y+5=0 X 2
Kx+6y+7=20

4x+6y+10=0
KX+6y+7=20
-
(4-k)X +0+3=-20
x =-23/[4-K]
x=23/k-4
from equation 2
Then y=13-23k/6[K-4]
Now from equation 1
2 [23/K-4+3[13-23k/6[K-4] +5=0


K=5

Answer 2

Given two equations -

2x + 3y + 5 = 0

kx + 6y + 7 = 20 ______( 1 )

On further solving ( 1 )

kx + 6y + 7 - 20 = 0

kx + 6y - 13 = 0

a1 = 2, a2 = k, b1 = 3, b2 = 6, c1 = 7, c2 = - 13

Condition for parallel lines -

a1 / a2 = b1 / b2

Putting values

2 / k = 3 / 6

2 / k = 1 / 2

k = 2 × 2

k = 4

^^'