作业帮4x²-{-3x²-[5x-x²-(2x²-x)]+4x},其中x=½
来源：学生作业帮助网 编辑：作业帮 时间：2024/04/30 09:05:25
![4x²-{-3x²-[5x-x²-(2x²-x)]+4x},其中x=½](/uploads/image/z/224428-4-8.jpg?t=4x%26%23178%3B-%7B-3x%26%23178%3B-%5B5x-x%26%23178%3B-%282x%26%23178%3B-x%29%5D%2B4x%7D%2C%E5%85%B6%E4%B8%ADx%3D%26%23189%3B)
4x²-{-3x²-[5x-x²-(2x²-x)]+4x},其中x=½
4x²-{-3x²-[5x-x²-(2x²-x)]+4x},其中x=½
4x²-{-3x²-[5x-x²-(2x²-x)]+4x},其中x=½
4x²-{-3x²-[5x-x²-(2x²-x)]+4x}
=4x²-[-3x²-(5x-x²-2x²+x)+4x]
=4x²-(-3x²-5x+x²+2x²-x+4x)
=4x²-(-2x)
=4x²+2x
=2x(2x+1)
当x=½ 时
原式=2
当x=½ 时
4x²-{-3x²-[5x-x²-(2x²-x)]+4x}=4x²+3x²+5x-x²-2x²+x-4x=4x²+6x
=4×(1/2)²+6×1/2=1+3=4