2.3.17

Factorise Quadratics

Test yourself on Factorise Quadratics

Test your knowledge with free interactive questions on Seneca — used by over 10 million students.

Factorising Quadratics

Follow these steps to factorise an expression of the form ax² + bx + c where a is not 1. We use 2x² + 10x + 8 as an example.

Step 1

Step 1

  • Work out the initial set of brackets. The coefficients of x must multiply to give a (a = 2 in this example).
Step 2

Step 2

  • Find pairs of numbers that multiply to give c (8 in this case).
Step 3

Step 3

  • Trial and error until you find a combination that works.
  • Try each pair both ways round (e.g. 2 in the 2x bracket or in the x bracket) and with different signs until you find a combination that results in the correct x coefficient in the expansion.
Step 4

Step 4

  • Always expand to check your answer works.
Jump to other topics
1

Number

1.1

Place Value

1.2

Factors & Multiples

1.3

Operations

1.4

Fractions, Decimals & Percentages

1.5

Growth & Decay

1.6

Measurements & Units

1.7

Accuracy

2

Algebra

2.1

Introduction to Algebra

2.2

Graphs

2.3

Solving Equations

2.4

Sequences

3

Ratio, Proportion & Rates of Change

4

Geometry & Measures

4.1

Introduction to Geometry

4.2

Ruler & Compass Constructions

4.3

Perimeter & Area

4.4

Triangles, Quadrilaterals & Circles

4.5

Transformations

4.6

Triangle Formulae

4.7

3D Shapes

4.8

Vectors

5

Probability

6

Statistics

Unlock your full potential with Seneca Premium

  • Unlimited access to 10,000+ open-ended exam questions

  • Mini-mock exams based on your study history

  • Unlock 800+ premium courses & e-books

Get started with Seneca Premium