If a x b = a/b - 1, then 7 x 28

Samantha swam upstream for some distance in one hour. she then swam downstream the same river for the same distance in only 12 minutes. if the river flows at 4 mph, how fast can samantha swim in still water?

Find the values of y: 3y^3(y^2+ 2/3y)=0

What is the equation of the line that is parallel to the line with the equation y= -3/4x +1 and passes through the point (12,-12)