Question

A line includes the points (3, 9) and (2, 3). What is its equation in slope-intercept form? Write your answer using integers, proper fractions, and improper fractions in simplest form.

Answer 1

y = 6x - 9

Explanation:

The slope-interce equation is;

y = m*x + b (1)

Where m is the slope, and b axis y intercept, to determine m, we use the coordinates of two different points.

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

P ( 3 , 9 ) Q ( 2 , 3 )

m = ( 3 - 9 ) / ( 2 - 3 ) ⇒ m = -6/ -1 m = 6

If Q is a point in the line, then plugging values in equation (1) of Q ( 2 , 3) and m, we get

y = m*x + b ⇒ 3 = 6*(2) + b ⇒ 3 = 12 + b

b = - 9

And the equation of the line is

y = 6x - 9