即x²+x+1/4=1260+1/4(x+1/2)²=5041/4x+1/2=±71/2x=-1/2±71/2所以x1=35，x2=-36
X+X^2=1260X^2+X+1/4=1260.25(x+0.5)^2=1260.25x+0.5=土35.5x1=35.5-0.5=35X2=-35.5-0.5=-36
