Question

(a-6)(a+9) -(a-4)(a-2)

Answer 1

(a-6)(a+9) -(a-4)(a-2)=(a^2+9a-6a-54)-(a^2-2a-4a+8)=a^2+3a-54-a^2+6a-8=9a-62

Answer 2

(a-6)(a+9)=a2+9a-6a-54-a2+2a+4a-8=9a-62