7x-(5x-5y)-y=______． 5．23a3bc2-15ab2c+8abc-24a3bc2-8abc=______． 6．-7x2+6x+13x2-4x-5x2=______． 7．2y+(-2y+5)-(3y+2)＝______． 11．(2x2-3xy+4y2)+(x2+2xy-3y2)=______． 12．2a-(3a-2b+2)+(3a-4b-1)=______． 13．-6x2-7x2+15x2-2x2＝______

7x-(5x-5y)-y=______． 5．23a3bc2-15ab2c+8abc-24a3bc2-8abc=______． 6．-7x2+6x+13x2-4x-5x2=______． 7．2y+(-2y+5)-(3y+2)＝______． 11．(2x2-3xy+4y2)+(x2+2xy-3y2)=______． 12．2a-(3a-2b+2)+(3a-4b-1)=______． 13．-6x2-7x2+15x2-2x2＝______
7x-(5x-5y)-y=______．
5．23a3bc2-15ab2c+8abc-24a3bc2-8abc=______．
6．-7x2+6x+13x2-4x-5x2=______．
7．2y+(-2y+5)-(3y+2)＝______．
11．(2x2-3xy+4y2)+(x2+2xy-3y2)=______．
12．2a-(3a-2b+2)+(3a-4b-1)=______．
13．-6x2-7x2+15x2-2x2＝______．
14．2x-(x+3y)-(-x-y)-(x-y)＝______．
16．2x+2y-[3x-2(x-y)]=______．
17．5-(1-x)-1-(x-1)=______．

7x-(5x-5y)-y=______． 5．23a3bc2-15ab2c+8abc-24a3bc2-8abc=______． 6．-7x2+6x+13x2-4x-5x2=______． 7．2y+(-2y+5)-(3y+2)＝______． 11．(2x2-3xy+4y2)+(x2+2xy-3y2)=______． 12．2a-(3a-2b+2)+(3a-4b-1)=______． 13．-6x2-7x2+15x2-2x2＝______
整式加减:去括号时,
①括号前面是减号,则化出来时要变号.
②括号前面是加号,则化出来时要不变号.
7x-(5x-5y)-y
=7x-5x+5y-y
=2x+4y
5
23a³bc²-15ab²c+8abc-24a³bc²-8abc 移项
=(23a³bc²-24a³bc²)-15ab²c+(8abc-8abc)
=-a³bc²-15ab²c
6
-7x²+6x+13x²-4x-5x²
=(-7+13-5)x²+(6-4)x
=x²+2x
7
2y+(-2y+5)-(3y+2) 去括号
=2y-2y+5-3y-2
=3-3y
11
(2x²-3xy+4y²)+(x²+2xy-3y²) 去括号
=2x²-3xy+4y²+x²+2xy-3y²
=3x²-xy+y²
12．2a-(3a-2b+2)+(3a-4b-1)
=2a-3a+2b-2+3a-4b-1
=2a-2b-3
13．-6x²-7x²+15x²-2x²
=(-6-7+15-2)x²
=0
14．2x-(x+3y)-(-x-y)-(x-y)
=2x-x-3y+x+y-x+y
=x-y
16．2x+2y-[3x-2(x-y)]
=2x+2y-(3x-2x+2y)
=2x+2y-3x+2x-2y
=x
17．5-(1-x)-1-(x-1)
=5-1-(1-x)-(x-1)
=4-(1-x)-(x-1)
=4-[(1-x)+(x-1)]
=4-0
=4