Răspuns:
[tex]a) \: \frac{4x}{ab} - \frac{6x}{ab} = \frac{ - 2x}{ab} \\ b) \: \frac{x}{y} \times \frac{3x}{ {y}^{2} } = \frac{3 {x}^{2} }{ {y}^{3} } \\ c) \: \frac{a(a + b)}{ {a}^{2} - {b}^{2} } - \frac{b(a - b)}{ {a}^{2} - b } = \frac{ {a}^{2} + ab }{ {a}^{2} - {b}^{2} } - \frac{ab - {b}^{2} }{ {a}^{2} - {b}^{2} } \\ \frac{ {a}^{2} + ab - ab + {b}^{2} }{ {a}^{2} - {b}^{2} } = \frac{ {a}^{2} + {b}^{2} }{ {a}^{2} - {b}^{2} } \\ d) \: \frac{a {b}^{2} }{xy} \times \frac{x}{b} = \frac{ab}{y} \\ e) \: \frac{(a - 2b)(a + 2b)}{x + 3y} \times \frac{(x + 3y)(x - 3y)}{ {(a + 2b)}^{2} } = \\ \frac{(a - 2b)(x - 3y)}{a + 2b} \\ f) \: ({ \frac{ {x}^{2} a}{ {y}^{5} {b}^{3} } })^{3} = \frac{ {x}^{6} {a}^{3} }{ {y}^{15} {b}^{9} } [/tex]
