5x²-3x-5=0 则 5x²-2x-[1÷(5x²-2x-5)]

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/27 19:12:54

5x²-3x-5=0 则 5x²-2x-[1÷(5x²-2x-5)]
5x²-3x-5=0 则 5x²-2x-[1÷(5x²-2x-5)]

5x²-3x-5=0 则 5x²-2x-[1÷(5x²-2x-5)]
5x²-3x-5=0
∴5x²-2x-5=x
∴5x²-2x-[1÷(5x²-2x-5)]
=x+5-1/x=(x²+5x-1)/x
=5(x²+5x-1)/5x
=(5x²+25x-5)/5x
=(5x²-3x-5+28x)/5x=28/5

5x^2-2x=x+5
5x^2-2x-5=x
所以原式=x+5-1/x
=(x^2+5x-1)/x
条件得到x^2-(3/5)x-1=0
x^2-1=(3/5)x
所以原式=(5+(3/5))x/x=5.6

5x²-3x-5=0则,5x²-3x=5.
5x²-2x-[1÷(5x²-2x-5)]
=5+x-1/(5-5+x)
=5+x-1/x
=(5x+x^2-1)/x