Unique point is obtained for the pair of equations a1x + b1y + c1 = 0 and a2x +b2y + c2 = 0 if
Condition satisfied by the pair of equation 2x+3y=−5 and 4x+6y−10=0 is
The condition for a pair of equations a1x+b1y+c1=0 and a2x+b2y+c2=0 to be parallel is