Find \(B - A\) if the graph of \(Ax + By = 3 \) passes through \((-7,2)\) and is parallel to the graph of \(x + 3y = -5\).
x+ 3y = -5 find slope, m when in the form y = mx+b
3y = - x -5
y = -1/3 x - 5/3 slope = -1/3 as is the parallel slope
y = -1/3 x + b
2 = -1/3 (-7) + b
2 = 7/3 + b
-1/3 = b
y = -1/3x - 1/3 re-arrange to 'Ay + Bx = 3' form
y + 1/3x = -1/3
-3y -x = 1
-9y-3x=3 B-A then equals -3 - - 9 = +6