`30+2,8:(4/25 - 9/15 -1/6)`
`=30+2,8 :( -11/25-1/6)`
`=30+14/5 :(-19/150)`
`=30-60/13`
`=330/13`
\(30+2,8:\left(\dfrac{4}{25}-\dfrac{9}{15}-\dfrac{1}{6}\right)=30+\dfrac{14}{5}:\dfrac{-91}{150}=30+\dfrac{-60}{13}=\dfrac{330}{13}\)
30+2,8: \(\left(\dfrac{4}{25}-\dfrac{9}{15}-\dfrac{1}{6}\right)\)
=30+2,8: \(\left(\dfrac{24}{150}-\dfrac{90}{150}-\dfrac{25}{150}\right)\)
=30+2,8: \(\left(\dfrac{24-90-25}{150}\right)\)
=30+2,8: \(\left(-\dfrac{91}{150}\right)\)
=30+ \(\dfrac{14}{5}\) . \(\left(-\dfrac{150}{91}\right)\)
=30+ \(\left(-\dfrac{60}{13}\right)\)
=\(\dfrac{330}{13}\)