Simultaneous Equations: WJEC GCSE Intermediate June 2023 Unit 2 Q17

Intermediate June 2023 Unit 2 Q17

WJECIntermediateCurrent spec4 marksSimultaneous Equations

17. Solve the following simultaneous equations using an algebraic (not graphical) method.
You must show all your working. [4]

\[\begin{aligned} 2x + 3y &= 16{\cdot}4 \\ 3x - 2y &= 7{\cdot}7 \end{aligned}\]

Mark scheme

Scheme	Marks	Comments
Method to eliminate one variable e.g. equal coefficients AND appropriate intention to add or subtract or use a method of substitution.	M1	Allow one error in one term (not the term with equal coefficients).
First variable found \(x = 4{\cdot}3\) or \(y = 2{\cdot}6\) or equivalent	A1	CAO Award A0 for expressing the final answers in a form such as \(y = \dfrac{33{\cdot}8}{13}\) .
Substitute to find the 2^nd variable.	m1	FT substitution of their ‘1^st variable’ if M1 gained.
Second variable found	A1	No marks for ‘trial and improvement’. No marks for an unsupported answer.