Answers

  • Brainly User
2014-09-28T15:18:20+05:30
Put x² - 5x = p
The given expression becomes 
3p² -2(p + 5) - 6
= 3p² - 2p - 16
= 3p² + 6p - 8p - 16
= 3p(p + 2) - 8(p + 2)
= (p + 2)(3p - 8)
Now put replace with x² - 5x, above becomes
= (x² - 5x + 2)((3x² - 15x - 8)

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2014-09-28T17:12:12+05:30
Since, x²- 5x is equal in both the cases

So, x²- 5x =a
Placing a,

3a² -2(a + 5) - 6 
= 3a² - 2a - 16 
= 3a² + 6a - 8a - 16 
= 3a(a + 2) - 8(a + 2)
= (a+ 2)(3a - 8)

Now replacing the value of a,we get

(x² - 5x + 2)(3x² - 15x - 8)
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