The form of the linear equation is
[tex]y=mx+b[/tex]
m is the slope of the line
b is the y-intercept
Since the slope of the line is -4, then
m = -4
[tex]y=-4x+b[/tex]
To find b substitute x and y in the equation by the coordinates of a point on the line
Since point (1, 2) lies on the line, then
x = 1
y = 2
[tex]\begin{gathered} 2=-4(1)+b \\ 2=-4+b \end{gathered}[/tex]
Add 4 to both sides
[tex]\begin{gathered} 2+4=-4+4+b \\ 6=b \end{gathered}[/tex]
Then the equation of the line is
[tex]y=-4x+6[/tex]
To put it in the slope point form use this form
[tex]y-y_1=m(x-x_1)[/tex]
m = -4
x1 = 1
y1 = 2
[tex]y-2=-4(x-1)[/tex]
The answer is
[tex]y-2=-4(x-1)[/tex]
