What is the equation in point-slope form of the line passing through (2, 5) and (–1, 8)?
1 Answer
May 30, 2015
Explanation:
First, we have to find the slope of the equation. To find the slope we have to do;
"slope" = m = (y_2-y_1)/(x_2-x_1)
For our question slope is;
m = (8-5)/(-1-2) = 3/-3 = -1
The equation of a line is;
y=ax+b
We should use one point to find the real equation. If we use
y= ax+b => 5=2a+b
5 = 2 * (-1) + b => 5= -2 +b => b=7
So the equation of the line will be;
y=ax+b => y= -x+7
We can check if our equation is right or not with other given point;
(-1,8) => y=-x+7 => 8=-(-1)+7 => 8=8