The given equation is
[tex]y=-3x+4[/tex]Notice that this equation represents a line in slope-intercept form, where its slope is -3.
Now, we have to find a new line parallel to the one above, which means the slope of the new line is also 3 because parallel lines have equal slopes.
Then, we use the given points (-4,6) and the slope -3 to find the equation
[tex]\begin{gathered} y-y_1=m(x-x_1) \\ y-6=-3(x-(-4)) \\ y-6=-3x-12 \\ y=-3x-12+6 \\ y=-3x-6 \end{gathered}[/tex]