Question

a(b-c)-b(c-a)+c(a-b),其中a=1，b=2，c=3

Answer 1

原式= ab-ac-bc+ab+ac-bc
=2ab-2bc
=4-12
=-8

Answer 2

a(b-c)-b(c-a)+c(a-b),
=ab-ac-bc+ab+ac-bc
=2ab-2bc
=2b(a-c)
=4×（-1）
=-8
祝学习进步