去括号:-(a-b)=______,-2(x-3y)=______,(52a2-3a+1)×3=______.-数学

题目简介

去括号:-(a-b)=______,-2(x-3y)=______,(52a2-3a+1)×3=______.-数学

题目详情

去括号:-(a-b)=______,-2(x-3y)=______,(
5
2
a2-3a+1)×3
=______.
题型:填空题难度:中档来源:不详

答案

-(a-b)=-a+b;
-2(x-3y)=-2x+(-2)×(-3y)=-2x+6y;
(class="stub"5
2
a2-3a+1)×3
=class="stub"5
2
a2×3+(-3a)×3+1×3=class="stub"15
2
a2-9a+3.
故答案分别为:-a+b;-2x+6y;class="stub"15
2
a2-9a+3.

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