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The quadratic formula

Free Printable The quadratic formula PDF Worksheets, Revision Guide & GCSE Past Paper Questions (Grade 7)

Download free the quadratic formula worksheets (PDF), GCSE maths past paper questions and worked solutions for The quadratic formula (7E). This is a Grade 7 algebra topic from the GCSE questions by topic collection for Higher tier GCSE Maths (Edexcel, AQA, OCR and IGCSE).

The free PDF worksheets table below brings together printable question booklets (Qs) and worked answers or mark schemes (Ans) from Maths Genie, Corbett Maths, Maths Made Easy, 1st Class Maths, Maths4EveryOne, Metatutor, Maths Takeaway, Maths DIY, Dr Austin, E Classroom and PMT, along with past paper question booklets.

Below the worksheet links you can read our the quadratic formula revision notes and worked examples with diagrams, try real GCSE past paper the quadratic formula questions with step-by-step solutions, or download a PDF of all the quadratic formula worksheet links.

Free The quadratic formula PDF Worksheets & Answers

Grade 7 • Topic 7E
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GCSE Maths Grade 7 Revision Notes & Method

Guide to The quadratic formula: Explanation, Diagrams & Worked Examples

Download Printable One Page Guide (PDF)

Explanation:

Use the quadratic formula x = −b ± √(b2 − 4ac)2a when a quadratic equation ax2 + bx + c = 0 cannot be easily factorised, or when the question asks for solutions to a given number of decimal places or significant figures, or in surd form.

Always rearrange the equation so that the right-hand side equals 0 first, then write down the values of a, b, and c including their signs. Put negative numbers in brackets when substituting into (−b)2 − 4(a)(c) so your calculator squares the negative sign properly.

Example 1: Solve 2x2 − 7x − 3 = 0 to 2 d.p.

Solution:

Here a = 2, b = −7, c = −3
x = −(−7) ± √((−7)2 − 4(2)(−3))2(2)
x = 7 ± √(49 + 24)4 = 7 ± √734
x = 3.8860... or x = −0.3860...
Answer: x = 3.89 or x = −0.39 (2 d.p.)

Example 2: Solve x2 + 6x = 4 in the form p ± √q.

Solution:

Rearrange to x2 + 6x − 4 = 0 (a = 1, b = 6, c = −4)
x = −6 ± √(62 − 4(1)(−4))2(1) = −6 ± √522
Since √52 = √4 × √13 = 2√13:
x = −6 ± 2√132 = −3 ± √13
Answer: x = −3 ± √13
Scanned GCSE Exam Questions & Worked Solutions

GCSE Past Paper The quadratic formula Questions & Answers

Past Paper Example 1 OCR Nov 2020 4H Q15 3 marks
(b) @@TABULAR0@@
Describe the error and write the correct solution.
(b) @@TABULAR0@@
Describe the error and write the correct solution.
[3 marks]
Worked Solution & Mark Scheme (3 marks)
Part (b) Solution:
Error: −b was not divided by 2a M2
Correct solution: x = (8 ± √(64 − 24)) / 4 = (8 ± √40) / 4 ⇒ x = 0.419 or x = 3.58 (3 s.f.). C1
Answer (b): Error: The −(−8) term should also be divided by 2 × 2 (the fraction line should go under the whole numerator).
Correct solution: x = (8 ± √40) / 4 ⇒ x = 0.419 or x = 3.58.
Past Paper Example 2 OCR Nov 2017 4H Q18 4 marks
Solve this equation algebraically.
Give your solutions correct to 2 decimal places.
3x2 + 5x - 1 = 0
Worked Solution & Mark Scheme (4 marks)
Using the quadratic formula with a = 3, b = 5, c = −1: M2
x = (−5 ± √(5² − 4 × 3 × (−1))) / (2 × 3) = (−5 ± √(25 + 12)) / 6 = (−5 ± √37) / 6. M1
x = (−5 + 6.08276) / 6 = 0.1804... ≈ 0.18, or x = (−5 − 6.08276) / 6 = −1.8471... ≈ −1.85. A1
Answer: x = 0.18 or -1.85
Past Paper Example 3 AQA Jun 2025 2H Q15 2 marks
Solve 3x2 + 5x - 9 = 0
Give your solutions as decimals.
Worked Solution & Mark Scheme (2 marks)
x = [–5 ± √(5² – 4(3)(–9))] / (2 × 3) = [–5 ± √133] / 6. M1
x ≈ 1.09 and x ≈ –2.76. A1
Answer: 1.09 and –2.76

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