Answer:
Q 6.
[tex]2x - x + 4(x - (x + 7) - 2) \\ x + 4(x - x - 7 - 2) \\ x + 4( - 9) \\ = x - 36[/tex]
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Q 7.
o 1)
[tex] \frac{ {x}^{2} - 4 }{5 - x} \times \frac{ {x}^{2} - 8x + 15}{ {x}^{2} - 5x + 6 } \\ \\ \\ \frac{(x + 2)(x - 2)}{5 - x} \times \frac{(x - 5)(x - 3)}{(x - 3)(x - 2)} \\ \\ \\ \frac{(x + 2)}{5 - x} \times \frac{(x - 5)}{1} \\ \\ \\ \frac{(x + 2)}{ - ( - 5 + x)} \times (x - 5) \\ \\ \\ \frac{(x + 2)}{ - (x - 5)} \times (x - 5) \\ \\ \\ \frac{(x + 2)}{ - 1} \\ \\ = - (x + 2) \\ \\ = - x - 2[/tex]
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o 2)
[tex] \frac{ {x}^{2} - 2x - 8 }{ {x}^{3} + 3 {x}^{2} } \div \frac{x - 4}{ {x}^{2} - 9} \\ \\ \\ \frac{ {x}^{2} - 2x - 8}{ {x}^{3} + 3 {x}^{2} } \times \frac{ {x}^{2} - 9 }{x - 4} \\ \\ \\ \frac{(x - 4)(x + 2)}{ {x}^{2}(x + 3) } \times \frac{(x + 3)(x - 3)}{x - 4} \\ \\ \\ \frac{x + 2}{ {x}^{2} } \times \frac{x - 3}{1} \\ \\ \\ = \frac{(x + 2)(x - 3)}{ {x}^{2} } \\ \\ \\ = \frac{ {x}^{2} - x - 6 }{ {x}^{2} } [/tex]
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Q 8.
a.
[tex]10 {x}^{2} + 7x - 12 \\ = (5x - 4)(2x + 3)[/tex]
