Higher June 2018 Paper 5 Q2
2 Gemma’s solution to the inequality \(3x + 1 \gt -5\) is shown on the number line.
Is Gemma’s solution correct?
Explain your reasoning. [3]
| Answer | Marks | Part marks and guidance | |
|---|---|---|---|
| Correct solution is \(x \gt -2\) | M2 | M1 for \(3x \gt -5 - 1\) oe or evaluates \(3x + 1\) correctly for \(x = -3\) or \(x = -4\), or \(x = -5\) or \(x = -6\) | For M2 accept in words, \(x\) is greater than −2, accept correctly drawn solution on a number line For M1 condone incorrect inequality sign or ‘equals’ e.g. \(x = -2\) implies M1 M1 implied by −8 or −11 or −14 or −17 |
| No and number line shows \(x \lt -2\) oe or No and draws the correct inequality on number line or No [the circle is correctly placed but] the arrow points the wrong way oe | A1 | After 0 scored, allow SC1 for number line shows \(x \lt -2\) oe isw or for [the circle is correctly placed but] the arrow points the wrong way oe | But for A1 or SC1 if just ‘it points the wrong way’ oe accept this provided there is no incorrect statement about where the circle should be placed and no incorrect working shown |