Intermediate November 2019 Unit 2 Q15
15. Solve the following simultaneous equations using an algebraic (not graphical) method.
\[\begin{aligned} 5x + 3y &= 11 \\ 2x - 7y &= 29 \end{aligned}\]You must show all your working. [4]
| Scheme | Marks | Comments |
|---|---|---|
| Method to eliminate variable e.g. equal coefficients with intention to appropriately add or subtract’ | M1 | No marks for ‘trial and improvement’. No marks for an unsupported answer. Allow 1 error in one term, not one with equal coefficients. |
| First variable found x = 4 or y = −3. | A1 | C.A.O. |
| Substitute to find the 2nd variable. | m1 | F.T. their ‘1st variable’. |
| Second variable found. | A1 |