Hint: you want the line passing through (0,0,0) with direction vector <2,-1,3>

Hint: you want the line passing through (2,1,0) with direction vector given by <1,1,0> X <0,1,1>, where X means the cross-product2) Find parametric and symmetric equations for the line through (2,1,0) and perpindicular to both i+j and j+k