Answer ধরি, `f(x) = 18x^3 + 15x^2 - x - 2`
তাহলে, `f(- 1/2) = 18 (- 1/2)^3 + 15(- 1/2)^2 - (- 1/2) - 2`
`= - 18 .1/2 + 15 . 1/4 + 1/2 - 2`
`= (- 9 + 15 + 2 - 8)/4`
`= (17 - 17)/4 = 0/4 = 0`
`:. {x - (- 1/2)} = (x + 1/2)`
অর্থাৎ (2x + 1), f(x) এর একটি উৎপাদক।
এখন, `18x^3 + 15x^2 - x - 2`
`= 18x^3 + 9x^2 + 6x^2 + 3x - 4x - 2`
`= 9x^2 (2x + 1) + 3x (2x + 1) - 2(2x + 1)`
`= (2x + 1) (9x^2 + 3x - 2)`
`= (2x + 1) (9x^2 + 6x - 3x - 2)`
`= (2x + 1) {3x (3x + 2) - 1(3x + 2)}`
`= (2x + 1) (3x + 2) (3x - 1)` (Ans)