Put 7x-5y+20 into slope intercept form

If given an equation of a line such as -1/2x+6 how would you create an equation of a line parallel and perpendicula to this line that goes through another point such as (4,10)

The appalachian trail is a hiking trail that passes through the appalachian mountains. three members of a teen hiking group hiked a section of the trail. the hikers stopped at a rest area and equally shared 3 4 gallon of water. how much water did each person get?

How do i do this activity, is appreciated