3a²b-[2a²b-﹙2ab-a²b﹚-4a²]-ab其中a=3.b=-2

3a²b-[2a²b-﹙2ab-a²b﹚-4a²]-ab其中a=3.b=-2
3a²b-[2a²b-﹙2ab-a²b﹚-4a²]-ab其中a=3.b=-2

3a²b-[2a²b-﹙2ab-a²b﹚-4a²]-ab其中a=3.b=-2
3a²b-[2a²b-﹙2ab-a²b﹚-4a²]-ab
=3a²b-2a²b+2ab-a²b+4a²-ab
=4a²+ab
=4×3²+3×(-2)
=30

-36

3a²b-[2a²b-﹙2ab-a²b﹚-4a²]-ab
=ab+4a²
=3×（-2）+4×3²
=-6+36
=30