15x" - 70x - 3000 = 0
3x" - 14x - 600 = 0
3x" + 36x - 50x - 600 = 0
3x( x + 12 ) - 50( x + 12 ) = 0
( x + 12 )( 3x - 50 ) = 0
解方程得
x1 = -12 ,
x2 = 50/3
15x" - 70x - 3000 = 0
3x" - 14x - 600 = 0
3x" + 36x - 50x - 600 = 0
3x( x + 12 ) - 50( x + 12 ) = 0
( x + 12 )( 3x - 50 ) = 0
解方程得
x1 = -12 ,
x2 = 50/3