<PRE><B>Question 1184529</B>
R * T = D


for tom, the formula becomes R * T = 15


for kim, the formula R * (T + 1) = 20


solve for R in both equations to get:


for tom, R = 15 / T


for kim, R = 20 / (T + 1)


since both equations are equal to R, then you get:


15 / T = 20 / (T + 1)


multiply both sides of the equation by T * (T + 1) to get:


15 * (T + 1) = 20 * T


simplify to get:


15 * T + 15 = 20 * T


subtract 15 * T from both sides of the equation to get:


15 = 20 * T - 15 * T


simplify to get:


15 = 5 * T


solve for T to get:


T = 3 hours.


T + 1 is therefore 4  hours.


for tom, R * 3 = 15.
solve for R to get:
R = 15/3 = 5 km per hour.


because the rate for each is the same, the two formulas now become:


for tom:


5 * 3 = 15 which becomes 15 = 15, which is true.


for kim:


5 * 4 = 20 which becomes 20 = 20, which is true.


the formulas are both true when R = 5 km per hour and T for tom is 3 and T for kim is 4.


your solution is that it takes tom 3 hours to get to work.




</PRE>