(1)12x-5=3x^2(公式法解)3x²-12x+5=0x²-4x=-5/3x²-4x+4=4-5/3(x-2)²=7/3x-2=±√(7/3)∴x=2±1/3√21（2）2（x-3）^2=x^2-9(f分解因式法解)2(x-3)²-(x-3)(x+3)=0(x-3)(2x-6-x-3)=0(x-3)(x-...