Question

求解答题答案及过程，万分感谢！

Answer 1

1、
(1) (-5a²)-a³-(-7a³)=-5a²+6a³=a²(6a-5)

(2) 3(a-b)²-7(a-b)+8(a-b)²+6(a-b)=11(a-b)²-(a-b)=(a-b)(11a-11b-1)

(3) 3x-2z-[-4x+(z+3y)]=3x-2z-[-4x+z+3y]=3x-2z+4x-z-3y=7x-3z-3y

2、15a²-{-4a²+[5a-8a²-(2a²-a)]+9a²-3a}
=15a²-{-4a²+[6a-10a²]+9a²-3a}
=15a²-{-4a²+6a-10a²+9a²-3a}
=15a²-{-5a²+3a}
=10a²-3a
=a(10a-3)

追问

符号是?

追答

=15a²-{-5a²+3a}
=15a²+5a²-3a}
=20a²-3a
=a(20a-3)