All the points lying inside the triangle formed by the points (1,3), (5,6) amd (-1,2) satisfy:

a)3x+2y_ 0 b) 2x+y+1_0 c) -2x+11_0 d)2x+3y-12_0

If your question is , 

All the points lying inside the triangle formed by the points (1,3), (5,0) and (-1,2), then 

the solution is as follows,

If all the three vertices of a triangle lie on one side of a line , all the interior points of that triangle lie on the same side of that line. 

Now, Substituting the coordinates of the points (1,3), (5,0) and (-1,2) in 3x+2y, we get the following values, 

8,15 and 1 which all are +ve.

therefore, all the points lying inside the triangle formed by given points satisfy 

3x+2y 0 

In the same way, all the points lying inside the triangle formed by given points also satisfy 

2x-3y-12 0