Two Brackets

Area models and special products

An interactive lesson with 9 steps, about 8 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• (x + a)(x + b) = x² + (a + b)x + ab: every term times every term.
• (a + b)² = a² + 2ab + b², never just a² + b².
• (a + b)(a − b) = a² − b², the difference of two squares.

Steps

1. Four rectangles
2. Expand
3. Work backwards
4. A squared bracket
5. Squaring in your head
6. The difference of two squares
7. Cut and turn
8. Around a hundred
9. Coefficients that aren’t 1