x·√(100-x²)=25√3 两边平方得x²(100-x²)=75-(x²)²+100x²=75(x²)²-100x²=-75(x²)²-100x²+50²=2500-75(x²-50)²=2425x²-50=±√2...数算错了吧（25√3）的方不是75吧最后结果是正负五吧，我刚刚算了一遍对，我算错了x·√(100-x²)=25√3 两边平方得x²(100-x²)=1875-(x²)²+100x²=1875(x²)²-100x²=-1875(x²)²-100x²+50²=2500-1875(x²-50)²=625x²-50=±25x²=50±25x²=25或75x1=5x2=-5 x3=5√3x4=-5√3