HOW are you given them?? If you are given their equations, then the equation of the plane should be something like: Ax+ By+ Cz= d while the ray would be given by parametric equations- x= at+ b, y= ct+ d, z= et+ f with t>= 0, say.
Put those equations for x, y, z, in terms of t, into the equation of the plane and solve the equation for t. If t>= 0, put it into the equations for the ray to find (x,y,z). If t<0 then the ray does not go through the plane- it goes the "away from" the plane.
(It is possible that the coefficient of t in the final equation will be 0. In that case the ray is parallel to the plane.)
Incase I have 3 points define a triangle (x1,y1,z1),(x2,y2,z2),(x3,y3,z3). And 2 points define a ray (xr1,yr1,zr1),(xr2,yr2,zr2). Could you tell me how can I check if that ray go through that triangle and the intersection point if they have? And more, if you could, please show me the best formula for that!