Question

помогите срочно пжпжпжпжпжп.
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Answer 1

a)

$\frac{5}{1 - 3x} - \frac{4}{3x - 1} = - \frac{5}{3x - 1} - \frac{4}{3x - 1} = - \frac{9}{3x - 1}$

б)

$\frac{5}{a + 4} + \frac{3 - 5a}{a {}^{2} + 4a} = \frac{5a}{a(a + 4)} + \frac{3 - 5a}{a(a + 4)} = \frac{5a + 3 - 5a}{a {}^{2} + 4a} = \frac{3}{a {}^{2} + 4a}$

в)

$\frac{4a {}^{2} }{a - b} - 4a = \frac{4a { }^{2} - 4a(a - b) }{a - b} = \frac{4a {}^{2} - 4a { }^{2} + 4ab }{a - b} = \frac{4ab}{a - b}$

г)

$\frac{16}{x - 4} - \frac{x {}^{2} }{x - 4} = \frac{16 - x {}^{2} }{x - 4} = \frac{(4 - x)(4 + x)}{x - 4} = \frac{ - ( x - 4)( 4 + x)}{x - 4} = - (4 + x) = - 4 - x$