1x²-4ax+3a²=1-2a →x²-4ax+（3a²+2a-1）=0→x²-4ax+（3a -1）（a+1）=0；分解因式得：（x-3a+1）（x-a-1）=0则：x1=3a -1； x2=a+1.2x²+5x+k²=2kx+5k+6→x²+（5-2k）x+（k...