[(x-1)(x+4)]²+(x+1)²=(x-3)²+[(x-1)(x-2)]²
问题描述:
[(x-1)(x+4)]²+(x+1)²=(x-3)²+[(x-1)(x-2)]²
请问x等于多少?
答
作差:[(x-1)(x+4)]²+(x+1)²-(x-3)²+[(x-1)(x-2)]²=(x-1)^2[(x+4)^2-(x-2)^2]+[(x+1)²-(x-3)²]=12(x-1)^2(x+1)+8(x-1)=4(x-1)(3(x^2-1)+2)=4(x-1)(3x^2-1)=0x=1或±根号3/3