How to solve an expression through substitution

  • Substitution means putting numbers in place of letters to calculate the value of an expression.
  • An expression can be a combination of numbers, letters and operators, grouped together.

Look at the examples below:


If \(a~=~2\) and \(b~=~5\)

Find \(3a~+~2b\)

How to solve the expression:


Substitute \(a\) with the value \(2\) and \(b\) with \(5\)