八年级数学二次根式易错题集锦

1大堰中学作业优化设计八年级数学二次根式易错题集1.有下列式子：①4；②110；④x；⑤21a；⑥5。其中一定是二次根式的是：__________________(只填序号)。2.若2)(11yxxx，则yx=_____________。3.bb3)3(3,则b的取值范围是________________.1)1(2aa成立的条件是________________________.4.计算aa1的结果是_________.计算)36(2=______.5.当0,0ba时,化简2)(baab的值为_________________.已知0xy,则化简yx2结果是_____________________.6.若等腰三角形两边长为50,12,则这个三角形的周长等于_______________________________.7.已知:3xy,则yxyxyx的值是______________________.8.)32(6=__________________________.9.若2)1()2()1(2xxxx则x的取值范围是________.10.(1-2)-2的算术平方根是________________________.11.已知2,3abba,计算baab的值.212.已知1018222xxxx则x的值是____________.13.已知实数a,b在数轴上的对应点分别为A,B,且A在原点左侧,B要原点右侧,如果ba,则2aba=_________.14.若,02mm则.__________42mm15.已知方程084myxx,当y0时,m的取值范围是______________________.16.已知a,b分别为等腰三角形的两条边长,且a,b满足aab23634,求此三角形的周长?17.已知,063yx则以x,y为两边长的等腰三角形的周长是__________.18.当1aa时,化简aa21)1(219.化简1)._______3a2).)0(43mnm=________.20.已知61xx,则_________1xx.21.已知31x,求代数式4)1(4)1(2xx值?322.已知x,y都是实数,且满足5.011xxy,化简11yy23.已知6969xxxx,且x为偶数,求145)1(22xxxx的值.24.若a,b为实数,且026104422baba,则ab10_____25.已知23,23cbba,求cabcabcba222的值