Question 49445
{{{ (a - 1) (a + 2) (a - 3) = a^3 - 2a^2 - 5a + 6 }}}

But how do i get that answer?
Thanks
use formula (a+x)(a+y)(a+z)=a^3+a^2(x+y+z)+a(xy+yz+zx)+xyz..or multiply normally...using formula 
a^3+a^2(-1+2-3)+a(-1*2-1*-3-3*2)+(-1)(3)(-2)
=a^3-2a^2-5a+6