How far is
how far 对距离提问.
How far is it from my home?这里到我家有多远呢?
It's 5 kilometers far away from my home.这儿到我家有五公里远.
spent getting
It takes us three hours to get there.（变同义句）
We spent three hours getting there.
我们花了三个小时到那里.（路上花去的时间是三个小时）
用代入法或消元法,
x=-3,y=1