Question

2000=500x-10x²-1000+200x等于多少？

Answer 1

2000=500x-10x²-1000+200x
解：500x+200x-10x²-1000-2000=0
700x-10x²-3000=0
x²-70x+300=0
判别式=（-70）²-4×300=4900-1200=3700
x1=（70+10√37）/2=35+5√37
x2=（70-10√37）/2=35-5√37

Answer 2

要解决这个方程，需要将所有项都移到左侧，得到：
-10x² + 500x - 800 = 0
然后，可以使用二次公式求解：
x = (-500±√(500²-4*(-10)(-800)))/(2(-10))
x = (-500±√(500²+3200))/(-20)
x = (-500±√80000)/(-20)
x = (-500±280)/(-20)
x = (-780)/(-20) = 39
x = (220)/(-20) = -11
因此，方程的两个解分别是 x = 39 和 x = -11。

Answer 3

2000=500x-10x²-1000+200x
10x²-700x+2000+1000=0
10x²-700x+3000=0
x²-70x+300=0
（x-35）²=35²-300
x-35=±√925
x1=35+5√37
x2=35-5√ 37