Find the value of B-A if the graph of Ax + By = 3 passes through the point (-7,2) and is parallel to the graph of x + 3y = -5.

We can plug the values of -7 and 2 into the equation and we get -7a + 2b = 3. The slope of a standard form equation is -a/b, and the sloper of x + 3y = -5 is -1/3, so a/b = 1/3, 3a = b. -7a + 2(3a) = 3. -a = 3, a = -3. b = -9.

Thus the value of B - A = -6.