An equation of the line passing through (4,10) and perpendicular to y=7x+9 is

I truly wish to help you, but I can't...

The line perpendicular  to the given one will have a negative -reciprocal slope = -1/7

So we have....using the point-slope form,

y - 10  = (-1/7) ( x - 4)   simplify

y = (-1/7)x + 4/7  + 10

y = (-1/7)x + 74/7       and that's the slope-intercept form