Intermediate November 2016 Unit 2 Q4
4.
(a) Solve the equation \(3x - 2 = 10\). [2]
(b) A number machine is shown below.
INPUT ⟶ ADD
5 ⟶ MULTIPLY
BY 7 ⟶ OUTPUT
(i) Calculate the OUTPUT when the INPUT is −2. [1]
(ii) Write down an expression for the OUTPUT when the INPUT is \(n\). [2]
| Scheme | Marks | Comments |
|---|---|---|
| 3x = 12 | B1 | |
| x = 4 | B1 | F.T. from 3x = k. x = 12/3 is B1B0 Allow an embedded answer. Mark final answer. |
| Scheme | Marks | Comments |
|---|---|---|
| (i) 21 | B1 | |
| (ii) 7(n + 5) or 7×( n + 5) or (n + 5)7 or (n + 5) × 7 or 7n + 35 | B2 | B1 for n + 5 × 7 OR 7 × n + 5. B0 for unsupported n + 35 OR unsupported 7n + 5. Mark final answer. |