7n + 7 = 42 help me please

5

Step-by-step explanation:

7n+7=42

7n=35

n=5

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