Question

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

Answer 1

Answer: -6

Step-by-step explanation:

$x+3y=-5\\\\3y=-x-5\\\\y=-\frac{1}{3}x-\frac{5}{3}$

So, since parallel lines have the same slope, the slope of the line we need to find is -1/3.

Substituting into point-slope form, the equation is

$y-2=-\frac{1}{3}(x+7)$

Converting to the required form,

$y-2=-\frac{1}[3}x-\frac{7}{3}\\\\\frac{1}{3}x+y=-\frac{1}{3}\\\\-3x-9y=3$

So, B-A is equal to -6.