Let t be a tetrahedron in standard position with three

Question

Question: Let T be a tetrahedron in "standard" position, with three edges along the three positive coordinate axes in R³, and suppose the vertices are ae₁, be₂, ce₃, and 0, where [e₁ e₂ e₃] = I3. Find formulas for the barycentric coordinates of an arbitrary point p in R³.