x+y+z=60,y+z+e=70,y+x+e=80,z+x+e=90

问题描述:

x+y+z=60,y+z+e=70,y+x+e=80,z+x+e=90
算式如何例!

x+y+z=60 (1)
y+z+e=70 (2)
y+x+e=80 (3)
z+x+e=90 (4)
相加
3(x+y+z+e)=300
x+y+z+e=100 (5)
(5)-(1),e=40
(5)-(2),x=30
(5)-(3),z=20
(5)-(4),y=10