Quadratic equations

Senior High 5 questions

What quadratic equations means

You solve equations where the highest power of x is 2. This helps you find unknown values quickly in school tests and exam questions.

What you will practise

Factorising simple quadratic expressions
Using the formula to find roots
Finding the discriminant from a, b and c
Checking answers by substitution

Before you start

You should already be able to work with indices, simplify algebraic expressions and solve basic linear equations. You also need confidence with multiplying brackets and rearranging equations.

Worked example

One question from this skill's own question bank, shown with its full working.

Question

Solve x squared minus 5x plus 6 equals 0.

x = 2 or x = 3
x = -2 or x = -3
x = 1 or x = 6
x = -1 or x = -6

Answer: x = 2 or x = 3

Working: Factorise into (x - 2)(x - 3) = 0, so x = 2 or x = 3.

Common mistakes to avoid

Forgetting to write the equation in the form ax² + bx + c = 0 before solving.
Missing one factor pair when factorising, so the roots come out wrong.
Using the wrong signs in the formula, especially for b and the square root.
Stopping after finding the discriminant and not using it to judge the roots.

Curriculum and exam alignment

Ghana GES SHS syllabusWASSCE

This topic normally appears in SHS 1 to SHS 3 algebra work, after learners have met basic equations and factorisation. It supports the type of problem-solving often set in WASSCE questions on quadratic roots and related checks.

Curriculum notes are a general guide to where this work normally sits. Always check the syllabus your school or examination body is currently using.