Question

A加B等于50,B加C等于60，A加C等于70，求A.B.C各是多少？

Answer 1

A+B=50
B+C=60
A+C=70
C-B=20
C=40 B=20 A=30

Answer 2

A+B=50; B+C=60; A+C=70; A=50-B; C=60-B; B=20; A=30; C=40

Answer 3

一个2元一次方程.