已知实数XYZ满足3X-y-3Z=0和X-6Y+6Z=0(Z不等于0),则代数式X+Y+Z/x-Y+Z的值等于
问题描述:
已知实数XYZ满足3X-y-3Z=0和X-6Y+6Z=0(Z不等于0),则代数式X+Y+Z/x-Y+Z的值等于
答
实数XYZ满足3X-Y-3Z=0① 和X-6Y+6Z=0 ②(Z不等于0)①×5 +②×6得:21x -41y + 21z=0即x + z = (41/21)y ③把③代入 X+Y+Z / x-Y+Z得【注:把x+z看成一个整体】(62/21)/(20/21)= 3.1即代数式X+Y+Z/x-Y+Z的值...