2ax的平方+（4a+3）x+2a+3=0
2ax²+4ax+3x+2a+3=0
2a(x²+2x+1)+3(x+1)=0
2a(x+1)²+3(x+1)=0
(x+1)(2ax+2a+3)=0
x1=-1,x2=-(2a+3)/2a