Grade 12 algebra questions and answers with step-by-step CAPS solutions for equations, inequalities, surds and quadratic problems.
Algebra is the foundation of CAPS Matric Maths. These practice questions cover quadratic equations, simultaneous equations, inequalities, exponents and surds — exactly the topics tested in NSC Paper 1. Question 1 of Paper 1 is usually pure algebra, so these skills set up your marks for the rest of the paper. Each solution shows the method a marker looks for. Cover the steps, attempt the question, then check.
Practice questions with solutions
Solve: 2x² − 7x + 3 = 0
Use quadratic formula
x = (7 ± √(49 − 24)) / 4
x = (7 ± 5)/4
Answer: x = 3 or x = 1/2
Simplify: (x³ · x⁵) / x²
Add exponents in numerator
Subtract exponent in denominator
Answer: x⁶
Solve: 3x − 4 ≥ 11
Add 4 to both sides
Divide by 3
Answer: x ≥ 5
Solve simultaneously: y = x + 1 and x² + y² = 13
Substitute y = x + 1: x² + (x + 1)² = 13
2x² + 2x − 12 = 0, so x² + x − 6 = 0
(x + 3)(x − 2) = 0, so x = −3 or x = 2
Substitute back: y = −2 or y = 3
Answer: (2; 3) or (−3; −2)
Solve: x² − x − 12 < 0
Factorise: (x − 4)(x + 3) < 0
Critical values: x = −3 and x = 4
The parabola opens upwards, so it is negative between the roots
Answer: −3 < x < 4
Simplify: √50 + √18
√50 = √(25 × 2) = 5√2
√18 = √(9 × 2) = 3√2
Add like surds
Answer: 8√2
Solve: 2ˣ⁺¹ = 32
Write 32 as a power of 2: 32 = 2⁵
Equate the exponents: x + 1 = 5
Answer: x = 4
For which value of k does x² + 4x + k = 0 have equal roots?
Equal roots means Δ = 0
Δ = b² − 4ac = 16 − 4k
16 − 4k = 0
Answer: k = 4
Solve: x(x + 3) = 10
Expand and rearrange: x² + 3x − 10 = 0
Factorise: (x + 5)(x − 2) = 0
Answer: x = −5 or x = 2
Solve: √(2x + 3) = x
Square both sides: 2x + 3 = x²
x² − 2x − 3 = 0, so (x − 3)(x + 1) = 0
Check: x = −1 gives √1 = 1 ≠ −1, so reject it
Answer: x = 3
Simplify: (2ˣ⁺² − 2ˣ) / (3 · 2ˣ)
Factorise the numerator: 2ˣ(2² − 1) = 3 · 2ˣ
Cancel the common factor 3 · 2ˣ
Answer: 1
Tips
Know the quadratic formula well, even though it is on the information sheet.
Always check for extraneous solutions when squaring.
Write a, b and c down before substituting into the formula.
Give inequality answers in the notation the question asks for.
Factorise completely before you cancel anything in a fraction.
Snap&Learn gives South African Matric learners instant, CAPS-aligned, step-by-step Mathematics solutions. Snap or upload a question and the AI shows every method mark the way the NSC memo awards them. Your first three AI solutions are free.