Answer :
3x^2 – 5x – 12 = (3x+4)(x-3)
x^2 -9 = (x-3)^2
8x^3+ 12x^2 - 2x - 3 = (4x^2 - 1)(2x + 3)
12x^2 +16x -3= (6x - 1)(2x + 3)
x^2 + 8x - 9= (x + 9)(x - 1) (I can not see who it can all be positive ;_; )
3(x + y) + a(x + y)= (3x + 3y) + (ax + ay)
x^2 -9 = (x-3)^2
8x^3+ 12x^2 - 2x - 3 = (4x^2 - 1)(2x + 3)
12x^2 +16x -3= (6x - 1)(2x + 3)
x^2 + 8x - 9= (x + 9)(x - 1) (I can not see who it can all be positive ;_; )
3(x + y) + a(x + y)= (3x + 3y) + (ax + ay)
7. 3x² - 5x - 12
3x² - 9x + 4x - 12
(3x + 4)(x - 3)
8. x² - 9
x² + 3x - 3x - 9
(x - 3)(x + 3)
9. 8x³ + 12x² - 2x - 3
(8x³ + 12x² - 2x - 3)
(4x² - 1)(2x + 3)
10. 12x² + 16x - 3
12x² + 18x - 2x - 3
(6x - 1)(2x + 3)
11. x² + 8x + 9
(x² + 9x - x + (-9))
(x - 1)(x + (-9))
Extra Credit: 3(x + y) + a(x + y)
3(x) + 3(y) + a(x) + a(y)
3x + 3y + ax + ay
3x + ax + 3y + ay
(3 + a)x + (3 + a)y
3x² - 9x + 4x - 12
(3x + 4)(x - 3)
8. x² - 9
x² + 3x - 3x - 9
(x - 3)(x + 3)
9. 8x³ + 12x² - 2x - 3
(8x³ + 12x² - 2x - 3)
(4x² - 1)(2x + 3)
10. 12x² + 16x - 3
12x² + 18x - 2x - 3
(6x - 1)(2x + 3)
11. x² + 8x + 9
(x² + 9x - x + (-9))
(x - 1)(x + (-9))
Extra Credit: 3(x + y) + a(x + y)
3(x) + 3(y) + a(x) + a(y)
3x + 3y + ax + ay
3x + ax + 3y + ay
(3 + a)x + (3 + a)y