Question 1077624
<pre>
input          1      2     3     4     n
output        -9    -11    -13   -15
</pre>
Increment 1 unit in input makes decrease 2 units in output.


r, result or output;
pick a ordered pair,  (1,-9).
SLOPE IS  {{{-2}}}.


{{{r-(-9)=-2(n-1)}}}

{{{r+9=-2n+2}}}

{{{r=-2n+2-9}}}

{{{highlight(r=-2n-7)}}}