`3,24 xx x  - 2,4 xx 0,38 = 21,12`

`3,24 xx x - 0,912 = 21,12`

`3,24 xx x = 21,12 + 0,912`

`3,24 xx x = 22,032`

`x=22.032 : 3.24`

`x=6,8`

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`x xx  37,5 + 62,5 xx x = 184,8 `

`x xx (37,5 + 62,5) = 184,8`

`x xx 100 = 184,5`

`x=184,5 : 100`

`x=1,845`

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`19,5 xx x - x xx 9,5 = 34,87`

`(19,5 - 9,5) xx x = 34,87`

`10 xx x = 34,87`

`x=34,87 : 10`

`x=3,487`

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