This study notes covers Worked Example 6: Negative Values (Tricky!) within Simplifying Expressions for GCSE Mathematics. Revise Simplifying Expressions in Algebra for GCSE Mathematics with 11 exam-style questions and 5 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 13 of 19 in this topic. Use this study notes to connect the idea to the wider topic before moving on to questions and flashcards.
Worked Example 6: Negative Values (Tricky!)
Find the value of 2x² − 3x when x = −2
Step 1 Substitute x = −2 with brackets!
= 2(−2)² − 3(−2)
Always use brackets around negative numbers!
Step 2 Work out the power
(−2)² = (−2) × (−2) = 4
= 2(4) − 3(−2)
Step 3 Complete the calculation
= 8 − (−6)
= 8 + 6
= 14
Remember: subtracting a negative = adding!
Practice questions for Simplifying Expressions
Which two terms are like terms?
Explain why 3x + 2x² cannot be simplified to 5x³.