Well there can be two different solutions for this but i will choose the easier one. Obviously one requires a system of equations which obviously will involve a lot of thinking and some good algebra solving in order for them to solve.
So we can just keep adding the distance as we know they are in different directions. 49 + 65 = 114. So 114 * 4.5 = 513 miles. SO after around 4.5 hours they will be 513 miles apart.
It would be great if you added some more details, but for common denominators you try to find the least common number that the 2 or more of the numbers you got have!
For example:
1/2 and 2/3 if you multiply 2 by 3 and 3 by 2, they both are 6, so you would multiply 1/2 both by 3 to make it into 3/6 and 2/3 by 2 to make it into 4/6!
Answer: Base angles theorem
Step-by-step explanation: