Question 4891
I think it means to take the given equation:

{{{3n - t = s}}} and solve for the varible that is after the semi-colon, which is "t."  This means getting all the "t" terms on one side and all the "non-t" terms on the other side. 


Start by subtracting 3n from each side of the equation:
{{{3n - 3n - t = s - 3n}}}
{{{-t = s - 3n}}}


Divide both sides by -1:
{{{ t = (s-3n) /(-1) }}}


To avoid negative denominator, multiply numerator and denominator by -1
{{{t = (-s + 3n)/ 1}}} = 3n - s


R^2 at SCC