不做說話的巨人，行動的矮子。說再多的漂亮話，也不如做一件實實在在的漂亮事，行動永遠是邁向成功的第一步，想永遠只會在原地踏步。對于考試而言亦是如此，每天進步一點點，基礎(chǔ)扎實一點點，通過考試就會更容易一點點。整理了“GRE數(shù)學(xué)重要知識點：Substitution”，歡迎閱讀參考！更多相關(guān)訊息請關(guān)注！
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.
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.