（x-4）^2=（5-2x）^2x²-8x+16=4x²-20x+25x²-8x+16-4x²+20x-25=0-3x²+12x-9=0x²-4x+3=0(x-1)(x-3)=0x=1或x=3
(x-4)^2=(5-2x)^2整理x^2-8x+16=25-20x+4x^2得3x^2-12x+9=0即x^2-4x+3=0分解因式（x-3)(x-1)=0解得x=3或x=1
