(a+6)(a-6)+(a-6)^2+(a-4)(a-1)
=(a-6)[(a+6)+(a-6)]+a^2-5a+4
=2a^2-12a+a^2-5a+4
=3a^2-17a+4
=3[a^2-(17/3)a]+4
=3(a-17/6)^2+4-289/36
=3(a-17/6)^2-145/36
=3[(a-17/6)^2-435/144]
=3(a-17/6-sqrt(435)/12)(a-17/6+sqrt(435)/12)
(a+6)(a-6)+(a-6)的平方+(a-4)(a-1). 分解因式