If D||D', D:2x - y = 1 and D':(a - 1)x + 2y = x - 2, then find the value of a.
Choose the most appropriate option:
A) -3
B) -2
C) -1
D) 0
E) 1
D:2x−y=1, D’:(a−1)x+2y=x−2   D:2x−y=1, D′:(a−1)x+2y=x−2   D∥D′⇒mD=m′   DD∥D′⇒mD=mD′   2x−y=1→y=2x−1→mD=22x−y=1→y=2x−1→mD=2   (a−1)x+2y=x−2→2y=x(1−a+1)−2→2y=x(2−a)−2→(a−1)x+2y=x−2→2y=x(1−a+1)−2→2y=x(2−a)−2→   y=x×(2−a)2−1→m′D=(2−a)2y=x×(2−a)2−1→mD′=(2−a)2   mD=m′D→(2−a)2=2→2−a=4→a=−2   ANSWER : -2 -2
<result>B</result>
If D||D', D:2x - y = 1 and D':(a - 1)x + 2y = x - 2, then find the value of a.