What is the length of DF

If 1 is divided by the sum of y& 4. the result is equal to 3 divided by 4 .find the value of m?

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?

Which point-slope form equation represents a line that passes through (3,-2) with a slope of -4/5