(b) Show the solution to \(\quad x^2 - 5x - 6 \lt 0 \quad\) on the number line. [1 mark]
Mark scheme (a)
Answer
Mark
Comments
\((x + 1)(x - 6)\) or \(\dfrac{5 \pm \sqrt{(-5)^2 - 4\ (\times 1) \times (-6)}}{2\ (\times 1)}\) or \(2.5 \pm \sqrt{12.25}\) or \(-1\) and 6 identified
M1
oe do not accept missing bracket on \((-5)^2\) unless recovered
\(-1 \lt x \lt 6\)
A1
condone \(-1 \lt x\) and \(x \lt 6\)
Mark scheme (b)
Answer
Mark
Comments
Open circles at \(-1\) and 6 joined by line
B1ft
ft their double-sided inequality in (a) if the bounds are within the number line condone ft an inequality given in two parts if the bounds are within the number line condone ft a single-sided inequality if the bound is within the number line
