Find the slope of the line that passes through 8,4 and 3,1

How is working backward similar to solving an equation?

Find the solution(s) to the system of equations. select all that apply y=x^2-1 y=2x-2

Kelli swam upstream for some distance in a hour.she then swam downstream the same river for the same distance in only 6 minutes.if the river flows at 5km/hr, how fast can kelli swim in still water?