Answer:
The equation of the line will be:
![y=(5)/(3)x-1](https://img.qammunity.org/2021/formulas/mathematics/high-school/tp0il1dghnbdyt70zv3kh2bhkmjfgdbr0j.png)
Explanation:
Given the points
Finding the slope between (3, 4) and (12, 9)
![\left(x_1,\:y_1\right)=\left(3,\:4\right),\:\left(x_2,\:y_2\right)=\left(12,\:19\right)](https://img.qammunity.org/2021/formulas/mathematics/high-school/cmgptpbppm0zhax67buv3b0z7r1tyspzeu.png)
![\mathrm{Slope}=(y_2-y_1)/(x_2-x_1)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/nrlo6m8wdo12tyt9h1mdgp9vd4866t2plg.png)
![m=(19-4)/(12-3)](https://img.qammunity.org/2021/formulas/mathematics/high-school/7c282odmi3slgu7pxh8qgk5nrxjxg56dvw.png)
![m=(5)/(3)](https://img.qammunity.org/2021/formulas/mathematics/high-school/napbxmduqrksxkz8je1p51tio6pvka8atv.png)
The equation of the line can be obtained using the point-slope form of the equation of the line
![y-y_1=m\left(x-x_1\right)](https://img.qammunity.org/2021/formulas/mathematics/middle-school/rcvszur2s3ju02p6yrv6wlbv0ka5o3fy58.png)
substituting the values m = 5/9 and the point (3, 4)
![y-4=(5)/(3)\left(x-3\right)](https://img.qammunity.org/2021/formulas/mathematics/high-school/q2fl8i4keoazknz9qktqk0j7fsxi6gl8fh.png)
![y-4+4=(5)/(3)\left(x-3\right)+4](https://img.qammunity.org/2021/formulas/mathematics/high-school/10z3d8e5d0wepgs5evv0ouyxhszqg4rw2x.png)
![y=(5)/(3)x-1](https://img.qammunity.org/2021/formulas/mathematics/high-school/tp0il1dghnbdyt70zv3kh2bhkmjfgdbr0j.png)
Therefore, the equation of the line will be:
![y=(5)/(3)x-1](https://img.qammunity.org/2021/formulas/mathematics/high-school/tp0il1dghnbdyt70zv3kh2bhkmjfgdbr0j.png)