Substitution
Pages
Substituting into an expression
Replacing each letter with a number, then evaluating in the right order.
Substituting negative numbers
Substituting a negative value with brackets, so the sign survives squaring.
Substituting into terms with powers
Why 3x² means square first then multiply by 3, so x = 4 gives 48 not 144.
Substituting into a formula
Using formulae such as v = u + at by substituting every known value.
Practice
Practice
Substituting into an expression
Replacing each letter with a number, then evaluating in the right order.
PracticeSubstituting negative numbers
Substituting a negative value with brackets, so the sign survives squaring.
PracticeSubstituting into terms with powers
Why 3x² means square first then multiply by 3, so x = 4 gives 48 not 144.
PracticeSubstitution review
Evaluating expressions and formulae at given values.