(x-5)(-50x+850)-250=1350

问题描述:

(x-5)(-50x+850)-250=1350

(x-5)(-50x+850)-250=1350
-50x²+850x+250x-4250-250=1350
-50x²+1100x-5850=0
x²-22x+117=0
(x-9)(x-13)=0
解得x1=9 x2=13