X+Y+Z=3.3
问题描述:
X+Y+Z=3.3
20X+15Y+12Z=51
12X+15Y+20Z=53.4
求X、Y、Z?
答
20X+15Y+12Z=51
12X+15Y+20Z=53.4
联立2方程得-X+Z=0.3
X+Y+Z=3.3 此乘以15X+15Y+15Z=49.5
15X+15Y+15Z=49.5
20X+15Y+12Z=51
联立这2个方程,得-5X+3Z=-1.5
-X+Z=0.3解,得X=1.2,Z=1.5,Y=0.6