二次根式的混合运算数学中国MathsChina.com,整理)52(321))(()35(35)2()(25233))((计算数学中国MathsChina.com,整理22200520067)(157)(2)(23)(23)(3)(25)(25)练习:(1)(1-51数学中国MathsChina.com,整理比较根式的大小.137146和提高题1.解:137146146()26+2+14=20+2√84√84()137220+29101460137又∵数学中国MathsChina.com,整理.23,23.222的值求,已知bababa2223232323解:原式6252362562516259想一想:还有其他方法吗?数学中国MathsChina.com,整理.23,23.222的值求,已知bababaabbabababa22222解二:abba2)(2323232321222918数学中国MathsChina.com,整理2.22.22.2.)(12,121.12DCBAxxx则若的值。求已知:xyyxxyyx,3,19.222D数学中国MathsChina.com,整理练习3计算:yxyxxybaab)4())(3()32153)(3235)(2()233)(1(22