Moderate -0.5 This is a straightforward simultaneous equations problem requiring substitution of one linear equation into another and basic algebraic manipulation. It's slightly easier than average as it's a standard C1 technique with no complications, though it requires careful arithmetic across 4 marks worth of working.
Question 4:
4 | 6x + 2(2x − 5) = 7
10x = 17
x = 1.7 o.e. isw
y = −1.6 o.e .isw | M1
M1
A1
A1 | for subst or multn of eqns so one pair of
coeffts equal (condone one error)
simplification (condone one error) or
appropriate addn/subtn to eliminate
variable
allow as separate or coordinates as
requested
graphical soln: M0 | 4
Find, algebraically, the coordinates of the point of intersection of the lines $y = 2x - 5$ and $6x + 2y = 7$. [4]
\hfill \mbox{\textit{OCR MEI C1 Q4 [4]}}