Resposta :
Olá, Malu Black.
[tex]1) 1,444...:1/3+7,101010....=(1+\frac49) \cdot 3 + 7 + \frac{10}{99}=\\\\=\frac{9+4}9\cdot 3+7+\frac{10}{99}= \frac{13}3+7+\frac{10}{99}=\frac{429+693+10}{99}=\frac{1132}{99}\\\\ 2) \sqrt{0,81}:\sqrt{0,25}+0,5:\sqrt{0,09}= 0,9:0,5+0,5:0,03=\\\\=\frac9{10} : \frac12+\frac12:\frac3{100}=\frac9{10} \cdot 2 +\frac12 \cdot \frac{100}3=\frac{9}{5}+\frac{50}3=\frac{27+250}{15}=\frac{277}{15}[/tex]
[tex]3) x=4,15:3,6=\frac{415}{100} \cdot \frac{10}{36}=\frac{83}{50} \cdot \frac{5}{18}=\frac{83}{180}\\\\ y=3,121212...:2,06=(3+\frac{12}{99}):\frac{206}{100}=\frac{297+12}{99} \cdot \frac{100}{206}=\frac{309}{99} \cdot \frac{50}{103}=\\\\= \frac{103}{33} \cdot \frac{50}{103} =\frac{50}{33}\\\\ z=8,101010...:2,545454...=(8+\frac{10}{99}):(2+\frac{54}{99})=\\\\=\frac{792+10}{99} \cdot \frac{99}{198+54} = \frac{892}{252}=\frac{223}{63}\\\\[/tex]