Answer
500 mi/h
Work Step by Step
time=$\frac{distance}{speed}$
time it took to get from Montreal to L.A. :$\frac{2500}{x}$
time it took to get from L.A. to Montreal :$\frac{2500}{1.2x}$=$\frac{2500}{\frac{6}{5}x}$=$\frac{12500}{6x}$
9h+$\frac{1}{6}$h = $\frac{2500}{x}$ + $\frac{12500}{6x}$
$\frac{55}{6}$ = $\frac{2500}{x}$ + $\frac{12500}{6x}$
multipy by 6x
55x=15000+12500
55x=27500
x=500
