Answer: b=-9
Step-by-step explanation:
To find the y-intercept of the line, we can use the points given to make an equation. To find the slope, you use the formula [tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex].
[tex]m=\frac{3-(-6)}{4-1} =\frac{9}{3} =3[/tex]
Now that we know the slope, we can fill in what we know and solve for y-intercept.
y=3x+b
We can plug in any point to solve for y-intercept.
3=3(4)+b [multiply]
3=12+b [subtract both sides by 12]
b=-9
Now, we know that the y-intercept is b=-9.
