Question

What is the equation of the line that passes through (5, 3) and (4, 5)

Answer 1

y = - 2x + 13

Explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (5, 3) and (x₂, y₂ ) = (4, 5)

m =
`(5-3)/(4-5)` =
`(2)/(-1)` = - 2, thus

y = - 2x + c ← is the partial equation

To find c substitute either of the 2 points into the partial equation

Using (4, 5), then

5 = - 8 + c ⇒ c = 5 + 8 = 13

y = - 2x + 13 ← equation of line