①成串____(A.chuàn B.cuàn)
②践爪____(A.zhuǎ B.zhāo)
③蛟龙____(A.jiāo B.jiǎo)
求下列各式中x的值.
(1)x2=5
(2)x2﹣5=49
(3)(x﹣2)2=125
(4)(y+3)3+64=0.