[tex]e) \\ \frac{9y {}^{4} }{ - 3y {}^{3} } = \frac{ - 3y {}^{4} }{y {}^{3} } = - 3y {}^{4 - 3} = \boxed{\boxed{\boxed{ - 3y}}} \\ f) \\ \frac{2xy {}^{4} }{ - 0,5y {}^{2} } = \frac{4x y{}^{4} }{y {}^{2} } = 4xy {}^{4 - 2} = \boxed{\boxed{\boxed{4xy {}^{2} }}} \\ g) \\ \frac{ - 7am}{ - 21am} = \frac{ - 7 \: . \: 1}{ - 21} = \frac{ - 7}{ - 21} = \boxed{\boxed{\boxed{ \frac{ 1}{3} }}} \\ [/tex]

att. yrz