Question

7/a+a-7/a+5
2x²/x²-4-2x/x+2 ​

Answer 1

а)

$\frac{7}{a} + \frac{a - 7}{a + 5} = \frac{7(a + 5) + a(a - 7)}{a(a + 5)} = \frac{7a + 35 + {a}^{2} - 7a}{a(a + 5)} = \\ = \frac{ {a}^{2} + 35 }{ {a}^{2} + 5a }$

б)

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