4x^4-25x^3+576=0
其中涉及到了x 的四次方,三次方,怎么解,要有过程,谢谢
參考答案:先两边同乘5,20x^4-125x^3+2880=0,
也就是 20x^4-125x^3+(8000-5120)=0,
(20x^4-5120)+(8000-125x^3)=0,
20(x^4-256)+125(64-x^3)=0,
20(x^2-16)(x^2+16)+125(4-x)(16+x^2+4x)=0,
20(x-4)(x+4)(x^2+16)+125(4-x)(16+x^2+4x)=0,
(x-4){20(x+4)(x^2+16)+125(16+x^2+4x)}=0,可得,x1=4,
剩下的用中学的知识解有点难,还没想到@_*