Verified Answer :

(x-3)(x-6)=x^2-6x-3x+18=x^2-9x+18

(x - 3)(x - 6)

= x(x - 6) - 3(x - 6)
 
= xx - 6x - 3x - 3-6

= x² - 6x - 3x + 18

= x² -9x + 18

Hope this explains it.