Question 280553
There is nothing wrong with your equation
450=(r+15)*(t-1)
You forgot the original info.
r*t=450
r=75 and t=6
check
r*t=450

75*6=450
450=450
now check the second equation
90*5=450
450=450
ok
The trip would not have been one hour less because Amy would have gotten stopped and ticketed or most likely ended up as a traffic fatality (dead).
What a terrible problem for math!