去括号,得 4x 2 +4x+1+5(x 2 -2x+1)=9x 2 -4-2, 4x 2 +4x+1+5x 2 -10x+5=9x 2 -4-2, 移项,得 4x 2 +4x+9x 2 +5x 2 -10x=-4-2-1-5, 合并同类项,得 -6x=-12, 化系数为1,得 x=2