(ii) 3x - 5y - 4 = 0 and 9x = 2y +7​

Step-by-step explanation:

                         3x - 5y = 4 ----------- ( 1 )

                         9x - 2y = 7 -----------( 2 )

                 ______________________

( 1 ) x 9  =>       27x - 45y = 36   ----------------- ( 3 )

( 2) x 3 =>        27x - 6y = 21     -------------------( 4 )

                  _____________________

( 3 )  =>          27x - 45y = 36

- ( 4 ) =>         -27x + 6y = - 21

                   ____________________

( 3 ) - ( 4 ) =>     0x - 39y = 15

                            -39y = 15

Substitute y in ( 1 ) :

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