I need help showing the work to solve this problem

Question

A plane left New York and flew toward the airshow at an average speed of 196 mph. a cargo plane left three hours later and flew in the same direction but with average speed of 490 mph. Find the number of hours the Air Force plane flew before the cargo plane caught up.

Answer 1

distance=rate*time

d=r*t

d=196*t (plane)

d=490*(t-3) (cargo plane)

equate the two right sides

196t=490(t-3)

196t=490t-1470

196t-490t=-1470

-294t=-1470

294t=1470

t=1470/294

t=5 hours (answer)