1.

Factorise 9x^2 + 4y^2 + 16z^2 + 12xy - 16yz -24xz

Answer»

Answer:

(3x+2y-4z)(3x+2y-4z)

Step-by-step explanation:

GIVEN an ALGEBRAIC expressionsuch that,

9 {x}^{2}  + 4 {y}^{2}  + 16 {z}^{2}  + 12xy - 16yz - 24xz

To factorise it.

Further simplifying, we can write it as,

=  {(3x)}^{2}  +  {(2y)}^{2}  +  {( - 4z)}^{2}  + 2(3x)(2y) + 2(2y)( - 4z) + 2(3x)( - 4z)

But, we KNOW that,

{a}^{2}  +  {b}^{2}  +  {c}^{2}  + 2ab + 2bc + 2ac =  {(a + b + c)}^{2}

Therefore, we will GET,

=  {((3x) +( 2y )+ ( - 4z))}^{2}  \\  \\  =  {(3x + 2y - 4z)}^{2}

Hence, the required VALUE is (3x+2y-4z)(3x+2y-4z).

Some more identities :-

  • {(x + y)}^{2}  =  {x}^{2}  + 2xy +  {y}^{2}
  • {(x - y)}^{2}  =  {x}^{2}  - 2xy +  {y}^{2}
  • (x + y)(x - y) =  {x}^{2}  -  {y}^{2}



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