hasil pengurangan 3x² – 2x dari 3 (-x² – 9x + 18)

3 x2 - 2x - 3 (-x2 - 9x + 18 )
= 3 x2 - 2x + 3 x2 + 27 x - 54
= 3 x2 + 3 x2 - 2 x + 27 x - 54
= 6 x2 × 25 x - 54