100x+70(120-x)=1600

问题描述:

100x+70(120-x)=1600

100x+70(120-x)=1600
100x+8400-70x=1600
30x=-6800
x=-680/3对不起是110x=70(120-x)=1600110x+70(120-x)=1600110x+8400-70x=160040x=-6800x=-170