Math, asked by Anonymous, 11 months ago

Factorize the following ⤵⤵

 {4x}^{3}  -  {4x}^{2}  - 21x 9
Solve the following sums with proper steps.​


AbhijithPrakash: Was it 21x raised to the power 9??
Anonymous: no its 21x -9
Anonymous: sorry
AbhijithPrakash: Ok

Answers

Answered by AbhijithPrakash
4

Answer:

\underline{\huge{\texttt{(2x + 1) (2x + 3) (x - 3)}}}

Step-by-step explanation:

where p = factor of constant (9) and q = factor of leading coefficient (4)

p = ±1, ±3, ±9

q = 1, 2, 4

Using trial and error, we find that 3 is a root

Now we use synthetic division to find quadratic factor:

3 | 4 -4 -21 -9

.. | .. 12 24. 9

.. ----------------

... 4 . 8 . 3 . 0

So dividing (4x^3 - 4x^2 - 21x - 9) by (x - 3), we get (4x^2 + 8x + 3)

(4x^3 - 4x^2 - 21x - 9) = 0 \\(x - 3) (4x^2 + 8x + 3) = 0 \\(x - 3) (4x^2 + 2x + 6x + 3) = 0 \\(x - 3) (2x (2x + 1) + 3 (2x + 1)) = 0\\ (x - 3) (2x + 1) (2x + 3) = 0 \\

x = 3, -1/2, -3/2


AbhijithPrakash: Hope This helps you...
Answered by aryankunalroy38
1

Answer:

4x³-4x²-21x-9=0

x(4x²-4x-21)-9=0

4x²-4x-21-9=0

4x²-4x-12=0

4(x²-x-3)=0

x²-x-3=0

then we use discriminant

I hope it help u☺️

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