prove function is continuous

If $\displaystyle f(x) = 5x - 6$, prove that f is continuous in its domain.

So,

Pick any *http://www.mathcs.org/analysis/reals/symbols/epsi.gif > 0*. Take any sequence *{ xn }* converging to *c*. Then there exists an integer *N* such that

*|f(xn)-(5 c - 6)| = |5xn-6-5c+6| = 5|xn-c|<http://www.mathcs.org/analysis/reals/symbols/epsi.gif*

My question is, why do we have * |xn - c | < http://www.mathcs.org/analysis/reals/symbols/epsi.gif /5? Why not ** |xn - c | < http://www.mathcs.org/analysis/reals/symbols/epsi.gif? Where did the 5 come from?*

Thanks.