Question

1.（4x-3y)-[2（x-1）+2y-3] 2.(2a-5b)-{-3b-2[4a-2（3a-b）｝

1.（4x-3y)-[2（x-1）+2y-3]
2.(2a-5b)-{-3b-2[4a-2（3a-b）｝

Answer 1

1.（4x-3y)-[2（x-1）+2y-3]=4x-3y-(2x-2+2y-3)=4x-3y-(2x+2y-5)=4x-3y-2x-2y+5=2x-5y+5
2.(2a-5b)-{-3b-2[4a-2（3a-b）｝=2a-5b-[-3b-2(4a-6a+2b)]=2a-5b-[-3b-2(-2a+2b)]=2a-5b-(-3b+4a-4b)=2a-5b-(4a-7b)=2a-5b+4a+7b=6a +2b

Answer 2

1.（4x-3y)-[2（x-1）+2y-3]
=4x-3y-(2x-2+2y-3)
=4x-3y-(2x+2y-5)
=4x-3y-2x-2y+5
=2x-5y+3

2.(2a-5b)-{-3b-2[4a-2（3a-b）｝
=2a-5b-[-3b-2(4a-6a+2b)]
=2a-5b-[-3b-2(-2a+2b)]
=2a-5b-(-3b+4a-2b)
=2a-5b-(4a-5b)
=2a-5b+4a+5b
=6a

追问

4.12（m-1/3 n）+5（n-m）-4（1/2m+3） 5.2（a2 b+2b3-ab²）+3a3-(2a²b-3ab²+3a3)-4b3

Answer 3

(4x-3y)-[2(x-1)+2y-3]
=4x-3y-2x+2-2y+3
=2x-5y+5
(2a-5b)-{-3b-2[4a-2(3a-b)}
=2a-5b-{-3b-2[-2a+2b}
=2a-5b-{-3b+4a-4b}
=2a-5b+3b-4a+4b
=-2a+2b