作业帮计算：①-5(a²-2)-2(3a²+5) ②-2（ab-3a²）-[2b²-（5ab+a²）+2ab]
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/21 01:01:35
计算：①-5(a²-2)-2(3a²+5) ②-2（ab-3a²）-[2b²-（5ab+a²）+2ab]
计算：①-5(a²-2)-2(3a²+5) ②-2（ab-3a²）-[2b²-（5ab+a²）+2ab]
计算：①-5(a²-2)-2(3a²+5) ②-2（ab-3a²）-[2b²-（5ab+a²）+2ab]
解
-5(a²-2)-2(3a²+5)
=(-5a²-6a²)+(10-10)
=-11a²
-2(ab-3a²)-[2b²-(5ab+a²)+2ab]
=-2ab+6a²-(2b²-5ab-a²+2ab)
=-2ab+6a²-(2b²-a²-3ab)
=(-2ab+3ab)+(6a²+a²)-2b²
=7a²+ab-2b²