# MAT - Paper 2012 - Q1G

## Flashcards

Why shouldn’t you use matricies to tackle MAT questions like this?

Because there are no matricies in the exam spec, so the question has been written to be solved differently.

## \[y = \frac{4 - 2k}{k - 2}\]
Why can’t $y$ ever be positive?

For $4 - 2k$ to be positive, $k$ has to be less than $2$. However, when $k$ is less than $2$, $k - 2$ is negative.

You’ve rearranged some simulatenous equations and got

\[y = \frac{4 - 2k}{k - 2}\]
Why is still worth trying to substitute $k = 2$ back into the original equation?

Because $k = 2$ might be a special ‘singular’ case.