Linear/quadratic simultaneous equations
3 exam-style questions. Answers and the mark for each step are on the last page.
- Question 1
(a) Solve y = 2x + 1 and y = 2 simultaneously. Give both ordered pairs (x, y).
- Question 2
Solve the simultaneous equations and .
(a) Find both solutions, giving each as (x, y).
(b) Explain what the two solutions represent on a graph.
- Question 3
(a) The line y = kx 2 meets the curve y = 4x + 7 at exactly one point. Find both possible values of k.
Answers and marks
Question 1
(a) {(−1, −1), (3, 7)}
- M1 Establishing or an equivalent valid method.
- M1 Establishing or an equivalent valid method.
- A1 Correct answer: {(−1, −1), (3, 7)}
Question 2
(a) (2, 4) and (−2, −4)
- M1 Substitute y = 2x into the first equation.
- M1 Solve for x.
- A1 Correct answer: (2, 4) and (−2, −4)
(b) They are the two points where the line y = 2x crosses the circle of radius √20 centred at the origin.
- C1 Correct conclusion with supporting reasoning: They are the two points where the line y = 2x crosses the circle of radius √20 centred at the origin.
Question 3
(a)
- P1 Establishing or an equivalent valid method.
- P1 Establishing or an equivalent valid method.
- A1 Correct answer: