(45+5)Y=45X-5X

问题描述:

(45+5)Y=45X-5X
5X+5Y+45Z=15
45X+5(Y+Z)=15

5X+5Y+45Z=15,① 45X+4X+5X=15,
45X+5Y+5Z=15,② X=5/18=Z
(45+5)Y=45X-5X
50Y=40X,代入①得,
5Y=4X.Y=2/9
①-②= 所以,x=z=5/18,y=2/9
-40X+40Z=0,
X=Z.代入②