I have Points $M\_1(-1,1)$ and $M\_2(2,3)$. From applied formula:
$$y-y\_1=\frac{y\_2-y\_1}{x\_2-x\_1}(x-x\_1).$$

Solving that gives:
$$y-1=\frac{3-1}{2-(-1)}(x-(-1)).$$

which when solved becomes: $2x - 3y + 5 = 0$.

I cannot understand how I get that last result. Can you please explain