Tutu

Do not be so desperate..use your brain.... take two values for t (t=0) and t=1 and find two more points of the plane....for t=0 you will find that the point Q(1,2,3) lies on the plane and fot t=1 the point R(2,1,5) lies on the plane...then your problem is to find the equation of a plane given 3 points...easy....

the rest is really easy

MINOAS