7.设有x只鸡,有x只兔.
2x+4x=48
6x=48
6x除号6=48除号6
x=8
答：鸡、兔各有8只. 7.设有x只鸡,有x只兔.
2x+4x=48
6x=48
6x除号6=48除号6
x=8
答：鸡、兔各有8只.