Slope intercept form of a line is y=mx+b where m= slope and b=y-intercept.
Given slope:m= -4 and the line passes through (1,6).
Point slope form of a line is:

So, first step is to plug in m=-4, x1=1 and y1=6 in the above equation. So,
y-6=-4(x-1)
y-6=-4x+4 By distribution property.
y=-4x+4+6 Add 6 to each sides of the equation.
y=-4x+10
So, slope intercept form is y=-4x+10.