Question

x+x+x+y+y=6.4 y+y+y+x+x=7.1 怎么算?

Answer 1

x+x+x+y+y=6.4

y+y+y+x+x=7.1

3x+2y=6.4①

3y+2x=7.1②

两式相加

5x+5y=13.5

x+y=2.7

2x+2y=5.4

代入①x=6.4-5.4

x=1

代入②

x=7.1-5.4

x=1.7