Question

Дам 25 баллов!!!!!!!!!!!!!!!!

Answer 1

1)

$3 {x}^{2} - 12 = 3( {x}^{2} - 4) = 3(x - 2)(x + 2)$

2)

$2 {a}^{2} + 4ab + 2 {b}^{2} = 2( {a}^{2} + 2ab + {b}^{2} ) = 2 {(a + b)}^{2}$

3)

$- {a}^{2} - 2a - 1 = - ( {a}^{2} + 2a + 1) = - {(a + 1)}^{2}$

4)

$18 {a}^{2} - 27ab + 14ac - 21bc = 9a(2a - 3b) + 7c(2a - 3b) = \\ \\ = (9a + 7c)(2a - 3b)$

5)

$10 {x}^{2} + 10xy + 5x + 5y = 10x(x + y) + 5(x + y) = (10x + 5)(x + y) = \\ \\ = 5(2x + 1)(x + y)$

6)

$- 28ac + 35 {c}^{2} - 10cx + 8ax = 7c( - 4a + 5c) - 2x( 5c - 4a) = \\ \\ = (7c - 2x)(5c - 4a)$

7)

$6 {a}^{2} - 3a + 12ab = 3a(2a - 1 + 4b)$

8)

${x}^{2} - {y}^{2} + 2x + 2y = (x - y)(x + y) + 2(x + y) = (x + y)(x - y + 2)$

9)

$8 {x}^{2} - 2 {y}^{2} = 2(4 {x}^{2} - {y}^{2} ) = 2(2x - y)(2x + y)$

10)

${(x - 4)}^{2} - 9 {x}^{2} = (x - 4 - 3x)(x - 4 + 3x) = ( - 2x - 4)(4x - 4) = \\ \\ = - 2 \times 4(x + 2)(x - 1) = - 8(x + 2)(x - 1)$