Write intercept form of (1,-2) and (-3,1)

Question

The question is "Write the slope-intercept form of the equation of the line through the given points, 14) through: (1,-2) and (-3,1)

 

Answer 1

Hello Omar,

First use the slope formula to find the slope between the two points:

m = (y₂ - y₁) / (x₂ - x₁)

→ m = [1 - (-2)] / [-3 - 1]

= (3) / (-4)

= -3/4.

 

Now use either point with the slope, and plug into the slope intercept form to find the 'b' value.  I am going to use the point (1,-2).

y = mx + b

→ -2 = (-3/4)(1) +b

→ -2 = -3/4 + b

→ b = -5/4

 

Now plug in the the 'm' and 'b' values, leaving the 'x' and 'y' alone:

→ y = (-3/4)x - 5/4, which is what the problem wants.

 

Thank you for posting the question.

Michael E.