a) x² + 3x + 2 = x² + 2x + x + 2 = x(x+2) + x + 2 = (x+2)(x+1)
b) x² + 5x + 6 = x² + 3x + 2x + 6 = x(x+3) + 2(x+3) = (x+3)(x+2)
c) x² + 7x + 12 = x² + 4x + 3x + 12 = x(x+4) + 3(x+4) = (x+4)(x+3)
d) x² + 7x + 10 = x² + 5x + 2x + 10 = x(x+5) + 2(x+5) = (x+5)(x+2)
e) x² + 9x + 20 = x² + 5x + 4x + 20 = x(x+5) + 4(x+5) = (x+5)(x+4)
f) x² + 12x + 27 = x² + 9x + 3x + 27 = x(x+9) + 3(x+9) = (x+9)(x+3)
g) x² + 8x + 15 = x² + 5x + 3x + 15 = x(x+5) + 3(x+5) = (x+5)(x+3)
h) x² + 11x + 30 = x² + 6x + 5x + 30 = x(x+6) + 5(x+6) = (x+6)(x+5)
i) x² + 9x + 14 = x² + 7x + 2x + 14 = x(x+7) + 2(x+7) = (x+7)(x+2)
