Question

The line y = k x +b passes through the points A(–1, 3) and B(2, –1). Write the equation of the line.

Answer 1

First, you need to find the slope.

`(y1-y2)/(x1-x2)`

3 - (-1)/ (-1) - 2 = 4/(-3) *this is the slope aka the k value

Plug in the ordered pairs for y and x

3= -4/3(-1) + b

3 = 4/3 + b

3 - 4/3 = b

5/3 = b

Y= -4/3x + 5/3

Answer 2

• y = (- 4/3)x + 5/3 in slope-intercept form

• 4x + 3y = 5 in standard form

-----------------------

Find the slope, k first:

• k = (- 1 - 3) / (2 - (-1))
• k = - 4/3

Use point A and substitute the value of k into initial equation to find the value of b:

• 3 = (- 4/3)(- 1) + b
• 3 = 4/3 + b
• b = 3 - 4/3
• b = 5/3

The line is:

• y = (- 4/3)x + 5/3

If you need a standard form ax + by = c, then convert:

• 3y = - 4x + 5
• 4x + 3y = 5