easy
the equation of a line that passes through the point (x1,y1) and has a slope of m is
y-y1=m(x-x1)
find slope
slope between (x1,y1) and (x2,y2) is
(y2-y1)/(x2-x1)
given
(9,0) and (-7,-4)
slope=(-4-0)/(-7-9)=-4/-16=1/4
slope os 1/4
a point is (9,0)
x1=9
y1=0
y-0=1/4(x-9)
we can put it into slope intercept and standard form
slope intercept
y=(1/4)x-(9/4)
standard
minus 1/4x
-1/4x+y=-9/4
times -4
x-4y=9