[tex] \frac{225}{100} = \frac{9}{4} [/tex]
[tex]1 \frac{23 - 2}{90} = 1 \frac{21}{90 } = \frac{90 + 21}{90} = \frac{111}{90} = \frac{37}{30} [/tex]
2,25=225/100=9/4
1,2(3)=(123-12)/90=111/90=37/30
