To take this into account means that if we vary one variable while keeping another one fixed then the third one, since it depends on them, must also change somehow.

把这个约束条件考虑进去，其中一个可变，另外一个不变，第三个变量就一定会随着第一个变量的改变而发生改变。

youdao

There could be a provision that the mix of equities and fixed-income securities in each account would change over time: As one got older, the portion of funds invested in fixed-income instruments, such as bonds, would increase, thereby reducing stock market exposure.

FORBES: Fact and Comment

Next year Mexico's economy will be much more strongly placed than it was in 1994, with less debt falling due, a smaller current-account deficit, and a floating currency instead of a fixed one.

ECONOMIST: Mexico

Yodlee aggregates the user's account information into one place, providing that the user has accounts with the fixed list of sites included in Yodlee.

CNN: Digital wallets attempt to save time, headaches