Verified answer

[tex]3) \: \: \: \: \: \frac{y + \frac{3}{8} }{ \frac{7}{20} - \frac{7}{8} } = \frac{4}{7} \\ [/tex]

[tex]7(y + \frac{3}{8} ) = 4( \frac{7}{20} - \frac{7}{8} )\\ 7( \frac{8y + 3}{8} ) = 4( \frac{14 - 35}{40} ) \\ 7( \frac{8y + 3}{8} ) = 4( - \frac{21}{40} ) \\ \frac{56y + 21}{8} = - \frac{21}{20} \\ 1120y + 420 = - 168 \\ 1120y = - 168 - 420 \\ 1120y = - 588 \\ y = 0.525[/tex]

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[tex]4)[/tex]

[tex] \frac{ \frac{3}{4} + y}{ \frac{5}{6} - \frac{8}{9} } = - 9 \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \\ \frac{3}{4} + y = - 9( \frac{5}{6} - \frac{8}{9} ) \\ \frac{3 + 4y}{4} = - 9( \frac{15 - 16}{18} ) \\ \frac{3 + 4y}{4} = - 9 \times ( - \frac{ 1}{18} ) \\ \frac{3 + 4y}{4} = \frac{1}{2} \\ 6 + 8y = 4 \\ 8y = 4 - 6 \\ 8y = - 2 \\ y = - 0.25[/tex]