(x+4)根号2=(x+8)2(x^2+8x+16)=x^2+16x+642x^2+16x+32=x^2+16x+64x^2=32x=+-根号32x=+-4根号2取正,所以为4根号2,选D
(x+4)^2+(x+4)^2=(x+8)^22x^2+16x+32=x^2+16x+64x^2=32x=4√2所以选D
翻译一下,如果一个正方形的边长为x+4,对角线为x+8,求x值?不难得出 根号2倍(x+4)=x+8解出答案为D