Pre-U Pre-U 9794/1 2015 June — Question 2 5 marks

Exam BoardPre-U
ModulePre-U 9794/1 (Pre-U Mathematics Paper 1)
Year2015
SessionJune
Marks5
TopicSimultaneous equations
TypeLine intersecting general conic
DifficultyModerate -0.8 This is a straightforward simultaneous equations question requiring substitution of a linear equation into a conic (ellipse), then solving the resulting quadratic. It's a standard technique taught early in A-level with no conceptual difficulty—simpler than average since it involves routine algebraic manipulation with clean numbers and no geometric interpretation required.
Spec1.02c Simultaneous equations: two variables by elimination and substitution

2 Solve the following simultaneous equations. $$x ^ { 2 } + 2 y ^ { 2 } = 36 \quad x + 2 y = 10$$

Obtain correctly an equation in a single variable: \((10-2y)^2 + 2y^2 = 36\) [M1]
Obtain \(3y^2 - 20y + 32 (= 0)\) aef or equivalent in \(x\) [A1]
Solve their 3 term quadratic \(= 0\) [depM1]
Obtain any two values from \((2, 4)\) and \(\left(\frac{14}{3}, \frac{8}{3}\right)\) [A1]
Obtain \((2,4)\) and \(\left(\frac{14}{3}, \frac{8}{3}\right)\) [A1]
Total: [5]
Obtain correctly an equation in a single variable: $(10-2y)^2 + 2y^2 = 36$ [M1]
Obtain $3y^2 - 20y + 32 (= 0)$ aef or equivalent in $x$ [A1]
Solve their 3 term quadratic $= 0$ [depM1]
Obtain any two values from $(2, 4)$ and $\left(\frac{14}{3}, \frac{8}{3}\right)$ [A1]
Obtain $(2,4)$ and $\left(\frac{14}{3}, \frac{8}{3}\right)$ [A1]
**Total: [5]**
2 Solve the following simultaneous equations.

$$x ^ { 2 } + 2 y ^ { 2 } = 36 \quad x + 2 y = 10$$

\hfill \mbox{\textit{Pre-U Pre-U 9794/1 2015 Q2 [5]}}