Question 639189
3(s-t)^2


3(s-t)(s-t)


3(s(s-t)-t(s-t))


3(s^2-st-ts-t^2)


3(s^2-st-st-t^2)


3(s^2-2st-t^2)


3s^2-6st-3t^2


So 3(s-t)^2 simplifies to 3s^2-6st-3t^2