Question

Find the equation of the line joining the points A (1,2) and 8(-1,8)​

Answer 1

First, you need to find the slope between the two points:

`\begin{aligned}(8-2)/(-1-1) & = (6)/(-2)\\[0.5em]&=-3\endaligned}`

Now, you use one of the points to find the equation.

You can use point-slope form:

y - 1 = -3 (x-2)

Or you can use slope-intercept form:

y = -3x + 5

Note:

You can find the slope-intercept form by taking y = mx + b and substituting in the slope and a point and solving for b:

2 = -3 (1) + b