Answer:
Step-by-step explanation:
The slope-intercept form of an equation of a line:
[tex]y=mx+b[/tex]
m - slope
b - y-intercept
The formula of a slope:
[tex]m=\dfrac{y_2-y_1}{x_2-x_1}[/tex]
We have two points (1, -4) and (-2, 5).
Substitute:
[tex]m=\dfrac{5-(-4)}{-2-1}=\dfrac{5+4}{-3}=\dfrac{9}{-3}=-3[/tex]
Substitute the value of a slope and the coordinates of the point (1, -4) to the equation of a line:
[tex]-4=-3(1)+b[/tex]
[tex]-4=-3+b[/tex] add 3 to both sides
[tex]-4+3=-3+3+b[/tex]
[tex]-1=b\to b=-1[/tex]
Finally:
[tex]y=-3x-1[/tex]