Quadratic Equation Practice

Master quadratic equations with problems covering all solution methods. Learn when to factor, when to use the quadratic formula, and how to complete the square.

Grades 9-11GCSE to A-LevelÅrskurs 9 - Gymnasiet

Skills You'll Practice

  • Solving by factoring
  • Using the quadratic formula
  • Completing the square
  • Finding the discriminant
  • Solving quadratic word problems
  • Understanding the nature of roots

Solving by Factoring

Easy
1

x² - 9 = 0

💡 Show Hint

Difference of squares: (x+3)(x-3) = 0

✓ Show Answer

x = 3 or x = -3

2

x² + 5x = 0

💡 Show Hint

Factor out x: x(x+5) = 0

✓ Show Answer

x = 0 or x = -5

3

x² + 5x + 6 = 0

💡 Show Hint

Find two numbers that multiply to 6 and add to 5

✓ Show Answer

x = -2 or x = -3

Quadratic Formula

Medium
1

x² + 2x - 8 = 0 (use the formula)

💡 Show Hint

a=1, b=2, c=-8. Discriminant = 4+32 = 36

✓ Show Answer

x = 2 or x = -4

2

2x² - 5x - 3 = 0

💡 Show Hint

a=2, b=-5, c=-3

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x = 3 or x = -1/2

3

x² - 4x + 1 = 0

💡 Show Hint

Discriminant = 16-4 = 12

✓ Show Answer

x = 2 ± √3

Completing the Square

Hard
1

Solve by completing the square: x² + 6x + 5 = 0

💡 Show Hint

x² + 6x + 9 = -5 + 9 → (x+3)² = 4

✓ Show Answer

x = -1 or x = -5

2

Solve: x² - 8x + 7 = 0 by completing the square

💡 Show Hint

(x-4)² = 16 - 7 = 9

✓ Show Answer

x = 7 or x = 1

3

How many real solutions? x² + 4x + 5 = 0

💡 Show Hint

Check b² - 4ac = 16 - 20

✓ Show Answer

No real solutions (discriminant = -4)

Pro Tips

  • 💡Try factoring first—it's usually the fastest method when it works
  • 💡The quadratic formula ALWAYS works: x = (-b ± √(b²-4ac)) / 2a
  • 💡If discriminant > 0: two real solutions. = 0: one solution. < 0: no real solutions
  • 💡Completing the square is useful for finding vertex form and deriving the formula

Curriculum Alignment

CommonCore (HSA-REI.B.4)

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