=(x^2-5x)^2+10(x^2-5x)+24 =x^4-10x^3+25x^2+10x^2-50x+24 这是怎么转化的(X-1)(X-2)(X-3)(X-4) =(X-1)(X-4) (X-2)(X-3)=(x^2-5x+4)(x^2-5x+6)=(x^2-5x)^2+10(x^2-5x)+24=x^4-10x^3+25x^2+10x^2-50x+24=x^4-10x^3+35x^2-50x+24

问题描述:

=(x^2-5x)^2+10(x^2-5x)+24 =x^4-10x^3+25x^2+10x^2-50x+24 这是怎么转化的
(X-1)(X-2)(X-3)(X-4)
=(X-1)(X-4) (X-2)(X-3)
=(x^2-5x+4)(x^2-5x+6)
=(x^2-5x)^2+10(x^2-5x)+24
=x^4-10x^3+25x^2+10x^2-50x+24
=x^4-10x^3+35x^2-50x+24

利用乘法公式(a-b)^2=a^2-2ab+b^2有 ( x^2-5x)^2=(x^2)^2-2x^2*5x+(5x)^2=x^4-10x^3+25x^2 又10(x^2-5x)+24=10x^2-50x+24所以 (x^2-5x)^2+10(x^2-5x)+24=x^4-10x^3+25x^2+10x^2-50x+24...