45美元用英语表达就是：forty-five dollars.

例句：

It costs a bit more, forty-five dollars a person.

要贵一点，45美元一个人。

The first one sold for forty-five dollars.

第一台的价格是45美元。

相关例句：

They cost two dollars a pound.

这些东西每磅两元。

It'll cost at least 500 dollars.

这东西至少要花500元。

He inherited 10,000 U.S. dollars.

他继承了1万美元。

Do you have change for five dollars?

你有五元零钱吗？

She gets paid seven dollars an hour.

她的报酬是每小时7元。