0,2 ( 7 ) = ( 27 - 2 ) / 90 = 25 / 90 = ( 25 : 5 ) / ( 90 : 5 ) = 5 / 18
0,(15 ) = 15 / 99 = ( 15 : 3 ) / ( 99 : 3 ) = 5 / 33
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5 / 18 - 5 / 33 = ( 11 x 5 ) / ( 11 x 18 ) - ( 6 x 5 ) / ( 6 x 33 ) =
= 55 / 198 - 30 / 198 =
= 25 / 198 =
= 0,12(62 )
cmmmc al numitorilor 18 si 33 = 18 x 11 = 198
