Simplify completely, showing the relevant rule.
- Use (a±b)²=a²±2ab+b²; retain the middle term.
- Write one intermediate line without skipping products or signs.
- The simplified form is 4x²-12x+9; explain each term.
- Use (a±b)²=a²±2ab+b²; retain the middle term.
- .
- Collect like terms to obtain 4x²-12x+9.
- Check the signs, coefficients and exponents in every term.
4x²-12x+9.
Check your work
- Show the rule and a complete intermediate line.
- Give an algebraically equivalent simplified expression.