Question

下列计算中，正确的是（　　）                                                              

A．        B．           C．           D．

Answer 1

B【考点】二次根式的加减法；二次根式的乘除法．                                       

【分析】分别利用二次根式乘法运算法则，以及二次根式加减运算法则求出答案．                    

【解答】解：A、﹣无法计算，故此选项错误；                                    

B、×=4，正确；                                                                            

C、2+无法计算，故此选项错误；                                                       

D、无法化简，故此选项错误．                                                        

故选：B．                                                                                          

【点评】此题主要考查了二次根式的加减与二次根式的乘除运算，正确掌握运算法则是解题关键．