Respuesta :
Given
- a line through (2, 7.5) and (-1, 0)
Find
- the line's equation in slope-intercept form
Solution
You can start with the 2-point form of the equation for a line:
... y = (y₂ -y₁)/(x₂ -x₁)·(x -x₁) +y₁
Filling in the given values, you get
... y = (0 -7.5)/(-1 -2)·(x -(-1)) +0
... y = 2.5(x +1) . . . . . simplify a bit
... y = 2.5x +2.5 . . . . slope-intercept form

First you find the slope with the 2 points: (2, 7.5) and (-1, 0)
y1-y2/x1-x2 so 7.5-0/2-(-1) which equals 2.5
Next you solve the slope intercept form equation to get b
y=m*x+b (m is the slope and b is the intercept)
7.5=2.5*2+b
b=2.5
So the equation is y=2.5x+2.5