下列各题去括号所得结果正确的是( )A.x2-(x-y+2z)=x2-x+y+2zB.x-(-2x+3y-1)=x+2x-3y+1C.3x-[5x-(x-1)
题型:单选题难度:简单来源:不详
下列各题去括号所得结果正确的是( )A.x2-(x-y+2z)=x2-x+y+2z | B.x-(-2x+3y-1)=x+2x-3y+1 | C.3x-[5x-(x-1)]=3x-5x-x+1 | D.(x-1)-(x2-2)=x-1-x2-2 |
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答案
根据去括号的方法可知, x2-(x-y+2z)=x2-x+y-2z,故A错误; x-(-2x+3y-1)=x+2x-3y+1,正确; 3x-[5x-(x-1)]=3x-5x-x-1,故C错误; (x-1)-(x2-2)=x-1-x2+2,故D错误. 故选B. |
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