Answer:
[tex]y = 4x - 12[/tex]
Step-by-step explanation:
The equation of a line has the following format:
[tex]y = mx + b[/tex]
In which m is the slope and b is the y-intercept(value of x when y = 0).
In this question:
Slope 4, which means that [tex]m = 4[/tex].
So
[tex]y = 4x + b[/tex]
Contains point (1,-8).
This means that when [tex]x = 1, y = -8[/tex]. We replace this into the equation to find b. So
[tex]y = 4x + b[/tex]
[tex]-8 = 4(1) + b[/tex]
[tex]b = -12[/tex]
So
[tex]y = 4x - 12[/tex]