Question

Descompuneti in factori :
a) $4 x^{2} -9$
   $16 x^{2} -25$
   $x^{2} - 49$
    $4 x^{2} -25$
   $x^{2} -64$
b) $x^{2} -100$
   $36-25 x^{2}$
   $49-4 x^{2}$
   $64-25 x^{2}$
  $81-49 x^{2}$
c) $x^{2} -121$
    $169 x^{2} -49$
   $81 x^{2} -49 y^{2}$
  $36 x^{2} -25 y^{2}$

Answer 1

a) (2x + 3)(2x - 3)
(4x + 5)(4x - 5)
(x + 7)(x - 7)
(2x + 5)(2x - 5)
(x + 8)(x - 8)
b) (x + 10)(x - 10)
(6 - 5x)(6 + 5x)
(7 + 2x)(7 - 2x)
(8 + 5x)(8 - 5x)
(9 + 7x)(9 - 7x)
c) (x + 11)(x - 11)
(13x + 7)(13x - 7)
(9x + 7y)(9x - 7y)
(6x + 5y)(6x - 5y) 

Answer 2

a-4x²-9=(2x-3)(2x+3)

16x²-25=(4x-5)(4x+5)

x²-49=(x-7)(x+7)

4x²-25=(2x- 5)(2x+5)

x²-64=(x- 8)(x+8)



b- x²-100=(x+10)(x-10)

36-25x²=(6-5x)(6+5x)

49-4x²=(7+2x)(7-2x)

64-25x²=(8+5x)(8-5x)

81-49x²=(9+7x)(9-7x)


c-x²-121= (x+11)(x -1)

169x²-49=(13x+7)(13x-7)

81x²-49y²=(9x+7y)(9x-7y)

36x²-25y²=(6x+5y)(6x-5y)