Foundation November 2020 Paper 1 Q14
14
(a) Solve \(\quad 6x - 11 = 13\) [2 marks]
(b) Simplify fully \(\quad (2 \times 4a) + 9 + \dfrac{15a}{3} - 7\) [3 marks]
| Answer | Mark | Comments |
|---|---|---|
| \(6x = 13 + 11\) or \(6x = 24\) or \(\dfrac{24}{6}\) | M1 | oe eg \(-6x = -13 - 11\) or \(-6x = -24\) or \(\dfrac{-24}{-6}\) |
| 4 | A1 |
Additional guidance
| Embedded answer, eg \(6 \times 4 - 11 = 13\) | M1A0 |
| 24 with no other working | M0A0 |
| Flow chart method, if 4 not given as the answer. \(x \to \times 6 \to -11 \to 13\) and \(13 \to +11 \to \div 6 \to x\) | M1A0 |
| Answer | Mark | Comments |
|---|---|---|
| \((2 \times 4a =)\ 8a\) | B1 | |
| \(\left(\dfrac{15a}{3} =\right) 5a\) | B1 | |
| \(13a + 2\) | B1ft | ft B1B0 or B0B1 for their \(8a +\) their \(5a + 9 - 7\) is in the form \(pa + q\) do not award with further incorrect work eg \(13a + 2 = 15a\) |
Additional guidance
| \(13a + c\) could come from incorrect working eg \(8a + 4 + 9 + 5a - 7 = 13a + 16\) (their \(8a\) is \(8a + 4\)) eg \(8a + 4 + 9 + 5a - 7 = 13a + 6\) (their \(8a\) is \(8a + 4\)) eg \(8a + 9 + 5a - 7 = 13a + 16\) eg \(13a + 16\) (no other working) | B0B1B0ft B0B1B1ft B1B1B0ft B1B1B0ft |
| \(6a + 9 + 5a - 7 = 11a + 2\) | B0B1B1ft |
| \(8a + 9 + 12a - 7 = 20a + 2\) | B1B0B1ft |
| \(8a + 9 + 5 - 7 = 8a + 7\) | B1B0B1ft |
| \(8a + \dfrac{15a}{3} + 7\) | B1B0B0ft |
| \(6a + 9 + 12a - 7 = 18a + 2\) | B0B0B0ft |
| \(6a + 5a + 16 = 11a + 16\) | B0B1B0ft |