Me! i don't really understand this

Solve for n? [tex]z = \frac{3}{4} mn[/tex]

Y=(x+3)(x-4)(x+1)^2 sulutions? multiplicity?

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. what distance from city a is the point where the truck and the car will meet?