题目内容
.
把多项式按字母a的降幂排列是________.
计算2a-(4b+3a)-( )=2b.
合并同类项:
9(x+y)-2(x+y)-8(x+y)=________
=_____
计算:____________.
填空:
①=______;
②=_____;
③=_____;
④=____;
⑤(2a-3b)(3a-4b)=_____.