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2 : 1 + 3 / ( 2 + 5/2 )

= 2 : 1 + 3 /( 4/2 + 5 /2 )

= 2 : 1 + 3 : 9/2

= 2 : 1 + 3 x 2/9

= 2 : 1 + 6 /9

= 2 / ( 9 + 6 ) / 9

= 2 : 15 /9

= 2 x 9 /15

= 18/15

= 6 /5

( 3 x + 2 ) / 3 - 5/2 = - 2 x /5 + 30/5

( 30 x + 20 ) /30 - 75/30 = - 12 x /30 + 180 /30

30 x + 12 x = 180 + 75

42 x = 255

x = 255/42 = 85/14