Proving two expressions are equivalent
Transform both sides or simplify their difference.
- State that the variable represents an integer when proving integer properties.
- Use algebra to cover every permitted value. Factor out the divisor or 2 when helpful.
- One counterexample disproves a universal statement; several examples do not prove it.
Example 1
Show these expressions are equivalent.
The expressions are equivalent for all .
Example 2
Show these expressions are equivalent.
The expressions are equivalent for all .
Your turn
Question 1 Expand the bracket. Collect the terms. The result matches the second expression for every .
Show these expressions are equivalent.
Check answer
The expressions are equivalent for all .
Question 2 Expand the bracket. Collect the terms. The result matches the second expression for every .
Show these expressions are equivalent.
Check answer
The expressions are equivalent for all .
Question 3 Expand the bracket. Collect the terms. The result matches the second expression for every .
Show these expressions are equivalent.
Check answer
The expressions are equivalent for all .
Question 4 Expand the bracket. Collect the terms. The result matches the second expression for every .
Show these expressions are equivalent.
Check answer
The expressions are equivalent for all .
Question 5 Expand the bracket. Collect the terms. The result matches the second expression for every .
Show these expressions are equivalent.
Check answer
The expressions are equivalent for all .
Show these expressions are equivalent.
The expressions are equivalent for all .
Show these expressions are equivalent.
The expressions are equivalent for all .
Show these expressions are equivalent.
The expressions are equivalent for all .
Show these expressions are equivalent.
The expressions are equivalent for all .
Show these expressions are equivalent.
The expressions are equivalent for all .