Question 1141342
Find the common difference d for this sequence. 7,3,-1,-5,-9

Find a formula in simplest form, for the nth term a sub n for the sequence

So, I know that the common difference is -4 but I do not know the formula.
<pre>Formula for specifc term of an AP: {{{matrix(1,3, a[n], "=", a[1] + (n - 1)d)}}}
                                   {{{highlight_green(matrix(4,3, a[n], "=", 7 + (n - 1)d, a[n], "=", 7 + (n - 1)- 4, a[n], "=", 7 - 4n + 4, a[n], "=", - 4n + 11)))}}} ------- Substituting {{{matrix(2,3, 7, for, a[1], - 4, for, d)}}}