a) 7x - 6x2 - 2
= -6x2 + 3x + 4x - 2
= -3x(2x - 1) + 2(2x - 1)
= (2x - 1) (2 - 3x)
b) x2 + 4x + 3
= x2 + x + 3x + 3
= x(x + 1) + 3(x + 1)
= (x + 1) (x + 3)
c) 2x2 + 3x - 5
= 2x2 - 2x + 5x - 5
= 2x(x - 1) + 5(x - 1)
= (x - 1) (2x + 5)
d) 16x - 5x2 - 3
= -5x2 + 10x + 6x - 3
= -5x(x - 2) + 3(x - 2)
= (x - 2) (3 - 5x)