（1）x²+（4根号2x）-1=0(x+2√2)²=1+8(x+2√2)²=9x+2√2=±3x=-2√2±3 2）2x²-4=7x2x²-7x=4x²-7/2x=2(x-7/4)²=2+49/16(x-7/4)²=81/16x-7/4=±9/4x=(7±9)/4x=4或x=-1/2...