分解因式下:X4-2X2-8 X2-3XY+2Y2 2X2-7X+3 X2+2X-15-AX-5A 解方程:1999X2-2000X+1=0 X2-14X+13=01949X2-1999X+50=0
问题描述:
分解因式下:X4-2X2-8 X2-3XY+2Y2 2X2-7X+3 X2+2X-15-AX-5A 解方程:1999X2-2000X+1=0 X2-14X+13=0
1949X2-1999X+50=0
答
这是什么啊 在明确些
答
1999X^2-2000X+1=0
X=1/1999,X = 1
X^2-14X+13=0
X = 1, X = 13
答
分解因式下:X4-2X2-8=(x²-4)(x²+2)=(x+2)(x-2)(x²+2)X2-3XY+2Y2=(x-2y)(x-y)2X2-7X+3=(2x-1)(x-3)X2+2X-15-AX-5A=(x+5)(x-3)-A(x+5)=(x+5)(x-3-A)解方程:1999X2-2000X+1=0(1999x-1)(x-1)=0x=1/1999...