Since more than 2 problems per thread is not allowed:

3. Find the coordinates of the vector x in relation with the base {(1,1,1),(1,1,0),(1,0,0)} if x=(1,-2,3)

4. The triangle ABC is given with A(3,2) B(2,5) C(6,6). Find the projection of ABC if it first rotates for angle pi/6 around the coordinate start(beginning) and then turns simetrically in relation to the line y=x

tnx