已知X减2的平方根是正负2，Y减2X减8的立方根是负3，求X减Y的算数平方根 已知x-2的平方根是正负2，y-2x-8的立方根是-3，求x...
\u5df2\u77e5x-2\u7684\u5e73\u65b9\u6839\u662f\u00b12\uff0cy-2x-8\u7684\u7acb\u65b9\u6839\u662f-3.\u6c42x-y\u7684\u5e73\u65b9\u6839x-2=2²=4\uff1b
x=6\uff1b
y-2x-8=-27;
y=2x+8-27=-7;
\u2234x-y\u7684\u5e73\u65b9\u6839\u4e3a\u6b63\u8d1f\u221a13\uff1b
\u5e0c\u671b\u5bf9\u4f60\u6709\u6240\u5e2e\u52a9\uff0c\u671b\u91c7\u7eb3
x-2=4 X=6 y-2x-8=27 y=47 x^2+y^2=36+2209=2245
X减2的平方根是正负2，Y减2X减8的立方根是负3∴x-2=(±2)²=4
y-2x-8=(-3)³
即x=6
y=-11
X减Y的算数平方根
=√﹙6+11)
=√17
绛旓細x鍑2鐨勫钩鏂规牴涓烘璐2 x-2=4 x=6 2x鍔爕鍔7鐨勭珛鏂规牴涓3 2x+y+7=27 2脳6+y+7=27 y=8 x骞虫柟鏍瑰姞y鐨勫钩鏂规牴 x骞虫柟鏍孤扁垰6 y鐨勫钩鏂规牴卤2鈭2 x骞虫柟鏍瑰姞y鐨勫钩鏂规牴 鈭6+2鈭2鎴栤垰6-2鈭2鎴-鈭6+2鈭2鎴-鈭6-2鈭2,1,8,0,
绛旓細x-2=4 y-2x-8=-27 x=6 y-12-8=-27 y=-7 棰樼洰涓嶅畬鏁
绛旓細x-2鐨勫钩鏂规牴鏄璐2 x-2=(姝ｈ礋2)鐨勫钩鏂=4 x=6 2x+y+7鐨勭珛鏂规牴鏄3 2x+y+7=3鐨3娆℃柟=27 2*6+y+7=27 y=27-7-12=8 x2+y2 =6鐨勫钩鏂+8鐨勫钩鏂 =36+64 =100
绛旓細宸茬煡x-2鐨勫钩鏂规牴鏄璐2锛2x+y+7鐨勭珛鏂规牴鏄3;鍒檟-2=4, 2x+y+7=27 瑙ｅ緱锛歺=6, y=8 鈭绰扁垰(x²+y²)=卤鈭(6²+8²)=卤鈭100 =卤10
绛旓細x-2鐨勫钩鏂规牴鏄璐2 鐭ワ細X=0;X=4;灏嗕袱鍊煎垎鍒甫鍏ワ紙2x+y+7鐨勭珛鏂规牴鏄3 锛夛細Y=-4;Y=-12;鍗筹細X=0锛孻=-4;x鐨勫钩鏂瑰姞y鐨勫钩鏂圭殑骞虫柟鏍=+-4锛沊=4锛孻=-12锛泋鐨勫钩鏂瑰姞y鐨勫钩鏂圭殑骞虫柟鏍=+-4*鏍瑰彿涓嬶紙10锛
绛旓細x-2鐨勫钩鏂规牴鏄璐2 鎵浠-2=(卤2)^2=4 x=6 2x+y+7鐨勭珛鏂规牴鏄3 鎵浠2x+y+7=3^3=27 2*6+y+7=27 y=8 鎵浠^2+y=36+8=44 鎵浠^2+y鐨勫钩鏂规牴=卤鈭44=卤2鈭11
绛旓細鈭x-2鐨勫钩鏂规牴鏄璐2, 2x+y+7鐨勫钩鏂规牴鏄3锛屸埓x-2=(卤2)²=4, x=6;2x+y+7=3²=9 鎶妜=6浠ｅ叆2x+y+7=9锛屽緱 12+y+7=9 y=-10 鈭磝鐨勫钩鏂癸紜y鐨勫钩鏂规牴=卤鈭(x²+y)=卤鈭(6²-10)=卤鈭26
绛旓細瑙 x-2鐨勫钩鏂规牴鏄卤2 鈭磝-2=(卤2)²=4 鈭磝=6 鈭2x+y+7鐨勭珛鏂规牴鏄3 鈭2x+y+7=3³=27 鍗12+y+7=27 鈭磞=8 鈭4x+3y+16=24+24+16=64 鈭4x+3y+16鐨勭珛鏂规牴鏄³鈭64=4,5,
绛旓細鍥犳眰X-2鐨勫钩鏂规牴寰梮-2澶т簬0锛屽緱x澶т簬2,鐢盭-2鐨勫钩鏂规牴鏄璐2寰梮1=4锛x2=0锛堜笉绗﹀悎棰樻剰鑸嶅幓锛夊皢x1=4浠ｅ叆2X锛Y锛7鐨勭珛鏂规牴鏄3寰y=12,鍒橷鐨勫钩鏂癸紜Y鐨勫钩鏂=4^2+12^2=16+144=160
绛旓細X-2鐨勫钩鏂规牴涓烘璐2 锛x-2)=(卤2)^2=4 x=6 3X+Y+3鐨勭珛鏂规牴涓3 3X+Y+3=3^3=27 y=6 X鐨勫钩鏂+Y鐨勫钩鏂圭殑骞虫柟鏍=鈭(6^2+6^2)=6鈭2
