Algebra (Higher)

The topic on one screen

• Quadratic inequalities: solve the equation first, sketch the parabola, then read the region — the sketch is what stops sign errors.
• $ax^2 - b < 0$ factorises as a difference of two squares more often than you'd think.
• Simultaneous equations from graphs: the solutions are the intersection points — read BOTH coordinates.
• Making $x$ the subject when $x$ appears twice: collect the $x$-terms on one side, factor $x$ out, divide. Three moves, every time.
• Perpendicular lines: gradients multiply to $-1$. Rearrange to $y = mx + c$ before comparing gradients.
• 'You must show all your working' means unsupported answers score zero — even correct ones.

Where students actually lose marks

Try it — exam-style

Questions are written in the style of past Edexcel papers (source shown on each) — never copied from them.

Drill it properly