Question

Determine the standard form of the equation of the line that passes through (-2,0) and (8,-5)

Answer 1

x + 2y = - 2

Explanation:

The equation of a line in standard form is

Ax + By = C ( A is a positive integer and B, C are integers )

Obtain the equation in slope- intercept form

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 ) = (- 2, 0) and (x₂, y₂ ) = (8, - 5)

m =
`(-5-0)/(8+2)` =
`(-5)/(10)` = -
`(1)/(2)`

y = -
`(1)/(2)` + c ← partial equation of line

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

Using (- 2, 0), then

0 = 1 + c ⇒ c = - 1

y = -
`(1)/(2)` x - 1 ← in slope- intercept form

Multiply through by 2

2y = - x - 2 ( add x to both sides )

x + 2y = - 2 ← in standard form