题目内容
【题目】对于有理数a,b定义a△b=3a+2b,化简式子[(x+y)△(x-y)]△3x
【答案】21x+3y
【解析】
整体根据定义a△b=3a+2b,先小括号,后中括号依次化简[(x+y)△(x-y)]△3x.
解:原式=[3(x+y)+2(x-y)]△3x
=(3x+3y+2x-2y)△3x
=(5x+y)△3x
=3(5x+y)+6x
=15x+3y+6x
=21x+3y.
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题目内容
【题目】对于有理数a,b定义a△b=3a+2b,化简式子[(x+y)△(x-y)]△3x
【答案】21x+3y
【解析】
整体根据定义a△b=3a+2b,先小括号,后中括号依次化简[(x+y)△(x-y)]△3x.
解:原式=[3(x+y)+2(x-y)]△3x
=(3x+3y+2x-2y)△3x
=(5x+y)△3x
=3(5x+y)+6x
=15x+3y+6x
=21x+3y.