Question

AB and BC form a right angle at point B. If A = (-3,-1) and B = (4,4), what is the equation of BC

Answer 1

Answer:

$y=-1.4x+9.6$

Step-by-step explanation:

If A = (-3,-1) and B = (4,4),  the slope of AB is

$\text{Slope}_{AB}=\dfrac{-1-4}{-3-4}=\dfrac{-5}{-7}=\dfrac{5}{7}$

Two perpendicular lines have slopes that have product of -1:

$\text{Slopee}_{AB}\cdot \text{Slope}_{BC}=-1\\ \\\dfrac{5}{7}\cdot \text{Slope}_{BC}=-1\\ \\\text{Slope}_{BC}=-\dfrac{7}{5}=-1.4$

The equation of the line BC with slope -1.4 and passing through the point B(4,4) is

$y-4=-1.4(x-4)\\ \\y-4=-1.4x+5.6\\ \\y=-1.4x+9.6$