下列去括号或添括号:①a2-5a-ab+3=a2-[ab-(3-5a)];②a-2(b-3c+1)=a2-2b+3c-1;③a2-5a-ab+3=(a2-ab)
题型:单选题难度:一般来源:不详
下列去括号或添括号: ①a2-5a-ab+3=a2-[ab-(3-5a)]; ②a-2(b-3c+1)=a2-2b+3c-1; ③a2-5a-ab+3=(a2-ab)-(5a+3); ④3ab-[5ab2-(2a2b-2)-a2b2]=3ab-5ab2+2a2b-2+a2b2, 其中正确的有( )个. |
答案
①a2-5a-ab+3=a2-[ab-(3-5a)]故本选项正确; ②a-2(b-3c+1)=a-2b+6c-2,故本选项错误; ③a2-5a-ab+3=(a2-ab)-(5a-3),故本选项错误; ④3ab-[5ab2-(2a2b-2)-a2b2]=3ab-[5ab2-2a2b+2-a2b2]=3ab-5ab2+2a2b-2+a2b2,故本选项正确; 其中正确的有①④; 故选B. |
举一反三
若-7xmy2与-3x3yn是同类项,则m-n=______. |
判断题. (1)x-(y-z)=x-y-z______ (2)-(x-y+z)=-x+y-z______ (3)x-2(y-z)=x-2y+z______ (4)-(a-b)+(-c-d)=-a+b+c+d______. |
若-a3b2m与4anb4是同类项,则n-m=( ) |
化简-[0-(2p-q)]的结果是( )A.-2p-q | B.-2p+q | C.2p-q | D.2p+q |
|
如果3x3m-三y与-x2y是同类项,那么m=______. |
最新试题
热门考点