For this case we have that the equation of a line of the slope-intersection form is given by:
![y = mx + b](https://img.qammunity.org/2020/formulas/mathematics/high-school/fc4cgm6covys37zv2opmmp9ps4jxyjepvh.png)
Where:
m: It's the slope
b: It is the cut-off point with the y axis
We found the slope:
![(x1, y1) :( 0,2)\\(x2, y2) :( 4,1)\\m = \frac {y2-y1} {x2-x1} = \frac {1-2} {4-0} = \frac {-1} {4} = - \frac {1} {4}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/bzrht5uffubp5nqfz211bwelb8axe52jzc.png)
Thus, the equation is of the form:
![y = - \frac {1} {4} x + b](https://img.qammunity.org/2020/formulas/mathematics/middle-school/zmzh681cvjn0uhw8y0l8vwwju2sdtj0a6u.png)
We find b, substituting any of the points:
![2 = - \frac {1} {4} (0) + b\\b = 2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/pk8uryofnz58ei7mi6iuvk5bta6cnspzus.png)
Finally, the equation is:
![y = - \frac {1} {4} x + 2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/t3o1yu55fz84um5c3yzpy50ph0povmmtai.png)
ANswer:
![y = - \frac {1} {4} x + 2](https://img.qammunity.org/2020/formulas/mathematics/middle-school/t3o1yu55fz84um5c3yzpy50ph0povmmtai.png)