1 1/10
2 设甲乙丙丁分别为XYZE
X+Y+Z+E=60
X=1/2(Y+Z+E)
Y=1/3(X+Z+E)
Z=1/4(X+Y+E)
求不等值,X=20 Y=15 Z=12 E=13
3 1/8X+15+1/5X-8=59 X=160