321 ÷ 40 long division what the answer showing work

There is a line with slope 1/a going through the point (a, a²). find the equation of the line perpendicular to this line at this point. (don’t let this problem intimidate you! solve the problem as you would if i’d given you specific values. just use variables instead.)

Sasha drank 8 bottles of water everyday for a week. how many bottles of water did she drink in total?

Choose the more precise measurement. 26.4 cm or 8.39 cm