Work out the value of a and the value of b
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Step-by-step explanation:
[tex]2 - \frac{x + 1}{x - 2} - \frac{x - 4}{x + 2} = \: \frac{ax + b}{x {}^{2} - 4 } \\ = \: \: 2 - \frac{(x + 1)(x + 2) - (x - 4)(x - 2)}{x {}^{2} - 4 } \\ = \frac{2x {}^{2} - 8 - x {}^{2} - 2x - x - 2 - x {}^{2} + 2x + 4x - 8 }{x {}^{2} - 4 } \\ = \frac{ - 8 - 2 + 3x - 8}{x {}^{2} - 4 } \\ = \frac{3x - 18}{x {}^{2} - 4 } \\ [/tex]
so, a = 3, b = -18