Question

A line passes through (2, −1) and (4, 5).

Which answer is the equation of the line?

Answer 1

y = 3x - 7

Explanation:

Use the equation y = mx + b where y is the y value, m is the slope, x is the x value, and b is the y intercept.

First find the slope between the two points.

`m = (-1 - 5)/(2 - 4) = (- 6)/(-2) = 3`

Choose a point and plug in the x value, y value, and m (slope) value in the equation to find the y intercept.

I will use the point (2, -1):

y = mx + b

-1 = (3)(2) + b

-1 = 6 + b

b = -7

Reassemble your equation with the slope and y intercept you found:

y = 3x -7