the equation of line is
-5x - y = 7
y = -5x-7
here the slope is m = -5
for parallel line the slope will be the same
so the equation of line that is parallel to the given line is
y = mx + c
put m = -5
y = -5x + c
it is given that y intercept is - 7
so the value of c will be 7
now the equation of line is
y = - 5x + 7