I have been trying to solve this question for a while, and I have no clue what I am doing wrong.
The question is
Find the Volume of a Tetrahedron with vertices $(1,3,5),(0,0,0),(a,0,0),(0,b,0)$.
Every time I try to find the equation of the plane to find the bounds for the integral, the $a,b$ disappears. Just doing it using geometry, I know it should be $\frac{5ab}{6}$, but I am getting crazy answers if I try to do triple integrals.
Thank you.