(i) 6x²+5x-6 

Using the splitting the middle term method,

We have to find a number whose sum = 5 and product = 6×-6 = -36

We get -4 and 9 as the numbers [-4+9 = 5 and -4×9 = -36]

6x² + 5x - 6 = 6x²+9x–4x–6

= 3x(2x+3)–2(2x+3)

= (2x+3)(3x–2)

(ii) 3x²–x–4 

Using the splitting the middle term method,

We have to find a number whose sum = -1 and product = 3×-4 = -12

We get -4 and 3 as the numbers [-4+3 = -1 and -4×3 = -12]

3x²–x–4 = 3x²–x–4

= 3x²–4x+3x–4

= x(3x–4)+1(3x–4)

= (3x–4)(x+1)