新版GRE数学复习重要考点：Substitution

本文为大家介绍的GRE数学复习考点是“代入法”。

新版GRE数学复习重要考点：Substitution

Substitution is a method where one or more variables in an expression is replaced by numbers or another set of variables.To evaluate an expression specific numbers are used as substitute. To express in terms of another set of variables, variables are replaced by the new set of variables.

Example:

If x=3, then 2x2+4x+1 can be evaluated by substituting 3 for x.

Replacing all x by 3, we get 2*3²+4*3+1=31.

If x=2+y, then x²-3 can be expressed in terms of y by replacing all x by (2+y):(2+y)²-3=y²+4y+1.

Remember:

Do not forget to replace all occurrences of the variable.

After substitution the variable does not appear anywhere in the expression.

>>点击查看GRE数学重要考点专题，阅读更多相关文章！

你可能还感兴趣的相关文章

• 如何两个月拿下GRE？

  每年都有无数小伙伴在纠结一个问题，两个月备考GRE到底够不够？事实上，全身心准备的话，完全够了。下面我们一起来看看如何备考，有哪些值得我们学习呢？

• GRE的文章源于哪里?
• GRE考前冲刺复习做到这5点提分最有效
• 2017年GRE考试报名开始啦！最新考试时间官方公布快来抢考位
• ETS官网查不了GRE分数怎么办？

最新2025GRE考试信息由沪江留学网提供。