Jawab:
[tex](1.)~~=\bf\frac{9}{10}=0,9\\\\\rm(2.)~~=\bf0,4=\frac{2}{5}\\\\\rm(3.)~~=\bf0,24=\frac{6}{25}\\\\\rm(4.)~~=\bf1\frac{3}{7}\\\\\rm(5.)~~=\bf1\frac{1}{7}[/tex]
Penjelasan dengan langkah-langkah:
[tex](1.)~~\frac{3}{4}\times1,2=\frac{3}{4}\times\frac{12}{10}=\frac{12}{4}\times\frac{3}{10}\\=3\times\frac{3}{10}=\bf\frac{9}{10}=0,9\\\\\rm(2.)~~0,8\times\frac{2}{4}=\frac{8}{10}\times\frac{2}{4}=\frac{8}{4}\times\frac{2}{10}\\=2\times\frac{2}{10}=\frac{4}{10}=\bf0,4=\frac{2}{5}[/tex]
[tex](3.)~~0,15\times\frac{8}{5}=\frac{15}{100}\times\frac{8}{5}=\frac{15}{5}\times\frac{8}{100}\\=3\times\frac{8}{100}=\frac{24}{100}=\bf0,24=\frac{6}{25}\\\\\rm(4.)~~\frac{4}{7}\div\frac{2}{5}=\frac{4}{7}\times\frac{5}{2}=\frac{4}{2}\times\frac{5}{7}=2\times\frac{5}{7}\\=\frac{10}{7}=\frac{7+3}{7}=\frac{7}{7}+\frac{3}{7}=1+\frac{3}{7}=\bf1\frac{3}{7}[/tex]
[tex](5.)~~\frac{8}{9}\div\frac{7}{9}=\frac{8}{\not9}\times\frac{\not9}{7}=\frac{8}{7}\\=\frac{7+1}{7}=\frac{7}{7}+\frac{1}{7}=1+\frac{1}{7}=\bf1\frac{1}{7}[/tex]
(xcvi)