Step-by-step explanation:
The equation of a line in slope-intercept form is:
![y=mx+b](https://img.qammunity.org/2023/formulas/mathematics/high-school/smsb8cbft03lwblmi49nf2l6jby2ofxzws.png)
Where m is the slope and b is the y-intercept.
The formula for the slope of a line with points (x1, y1) and (x2, y2) is:
![m=(y_1-y_2)/(x_1-x_2)](https://img.qammunity.org/2023/formulas/mathematics/college/fimp7zvgzwrq4ecowqytytl3ydbrfr5mz1.png)
In this case the slope is:
![m=(-4-2)/(3-1)=(-6)/(2)=-3](https://img.qammunity.org/2023/formulas/mathematics/college/3i3z77r7ll3xdi0zs1bwyvnnu814bu5zua.png)
For now we have:
![y=-3x+b](https://img.qammunity.org/2023/formulas/mathematics/college/4sbwu75cfh7n19kjzr6rp2h698eh3vse7u.png)
To find the y-intercept b, we have to replace (x,y) for one of the given points and solve for b. If we use point (1,2):
![\begin{gathered} y=-3x+b \\ \text{ replacing x = 1 and y = 2} \\ 2=-3\cdot1+b \\ 2=-3+b \\ b=2+3=5 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/olpi1f8ozhc1pu4cidbfns85ttcigpdfim.png)
Answer:
The equation of the line is: y = -3x + 5