Write an equation for the line through $A =(3, 1)$ and $B = (1, 2)$.

Question

The line passes through $B$ and is parallel to $B - A$. So, the equation is $X = B + t(B - A)$.

My question is: can we say that the following equations are correct as well?

$X = B + t(A - B).$

$X = A + t(B - A).$

$X = A + t(A - B).$