# Math Help - Please!! Solving system

Investigate for what values of k & c the following system 2x + 3y = 17, kx - y = c has either no simultaneous solution or more than one simultaneous solution.

2. Originally Posted by ttG
Investigate for what values of k & c the following system 2x + 3y = 17, kx - y = c
Think geometrically,for a change.
The equations correspond to equations of a line. So searching for simultaneous solutions is searching for intersections geometrically.

Originally Posted by ttG
has either no simultaneous solution
When will two straight lines in a plane never meet?

Originally Posted by ttG
or more than one simultaneous solution.
When will two straight lines in a plane meet at more than one point?
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Of course, you can do this using linear algebra too.

$\begin{vmatrix} 2 & 3 \\ k & -1 \end{vmatrix} = 0$ implies there exists "no simultaneous solution" or "more than one simultaneous solution."
So $k = -\frac23$
$kx - y = c \Rightarrow 2x+3y = -3c$

If
$-3c = 17$,
then equations are identical and we have "more than one simultaneous solution."
else
we have "no simultaneous solution".