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(1)12(2)(3)(4)2(3x-2x2y)-3(x-3x2y)(5)3a2-[8a-(4a-7)-2a2](6)

题目详情
(1)12(2)(3)
(4)2(3x-2x2y)-3(x-3x2y)(5)3a2-[8a-(4a-7)-2a2](6)
▼优质解答
答案和解析
(1)12 
=-×12+×12+×12
=-1+9+2
=10;
(2)
=--2××
=--
=-
(3)
=-1-4×(-27)÷
=-1-4×(-27)×
=-1-(-48)
=-1+48
=-47;
(4)2(3x-2x2y)-3(x-3x2y)
=6x-4x2y-3x+9x2y
=3x+5x2y;
(5)3a2-[8a-(4a-7)-2a2]
=3a2-[8a-4a+7-2a2]
=3a2-8a+4a-7+2a2
=5a2-4a-7;
(6)
=-2x+1-3+2x
=-2.