(35-x)(26-x)=850 即35*26-(26+35)x+x^2=850 即910-61x+x^2=850 即(35-x)(26-x)=850 即35*26-(26+35)x+x^2=850 即60-61x+x^2=0 即(x-60)(x-1)=0 即得x=60或x=1