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 $x + 3y = -5.$

2(10 - 13x) + 9x = -34x + 6020 - 26x + 9x = -34x + distributive property-17x = -34x + subtraction property (subtracted 20 from both sides)17x = addition property (added 34x to both sides)x = 40/ division property (divided both sides by 17)