3x7227x这题怎么做由3(x-7)2=2（7-x）得[3（x-7）+2]*(x-7)=0得x=19/3或x=7x3x-7*33x(x-7)=0.63x－21＝0.63x＝21.6x＝7.2先把x-7平方得x^2+49-14x再乘3得3x^2+237-42x=14-2x再解出x2，元气骑士付费人物兑换码有哪些《元气骑士》付费人物兑换码有：ltzjk、rkndrdvzbje3l、itzjrZ8088、owsd7pirkndrd、7rmshtintd06、scusnisblvbvh、ndaysk1528