X²-17.5x+75=0怎么解
1个回答

x²-17.5x+75 = 0 ,

(x-10)(x-7.5) = 0 ,【十字相乘法:10+7.5 = 17.5 ,10*7.5 = 75 】

x = 10 或 x = 7.5 .