A = (5x-2) (4x-3) - 7x (3-4x)
= (5x-2) (4x-3) -7×(-1)(4x-3)
= (4x-3)[(5x-2)+7x]
= (4x-3)(12x-2)
A = 2(4x-3)(6x-1)
B = (4x+1) (3x+6) + x (x +2)
= 3(4x+1) (x+2) + x(x+2)
= (x+2)[3(4x+1)+x]
= (x+2)(12x+3+x)
B = (x+2)(13x+3)
D = (x²-81) (3x-1) - 4 (3x+1) (x-9)
= (x+9)(x-9)(3x-1) - 4 (3x+1) (x-9)
=(x-9)[(x+9)(3x-1) - 4 (3x+1)]
= (x-9)(3x²-x+27x-9-12x-4)
D = (x-9)(3x²+14x-13)
E = 12x(au cube) - 3x
= 12x³-3x
= 3x(4x²-1)
E = 3x(2x-1)(2x+1)
F = 27x(au cube) - 36x² + 12x
= 27x³- 36x² + 12x
= 3x(9x²-12x+4)
F = 3x(3x-2)²
