How do I find the value of x for which line a is parallel to line b?

x = 20

Step-by-step explanation:

3x + 6x = 180, if you make them supplementary then they will be parallel

9x = 180

x = 20

it will cost dollar $540

the living room is 3 which means if we divide 325/3 then we get $108

therefore if 1part of the living room cost $108 and 3 costed $325

then total 5part of the room will cost 5*108 which gives $540