HELP RNN. Before 11:59 please y’all ty

Jamie is hiking up a small mountain. he climbs up at a constant rate of 300 feet/hour until he reaches the peak at 1,500 feet. after that, he hikes down at the same rate to the base of the mountain. the equation that models jamie’s elevation, e, after t hours is e = . jamie’s elevation will be 600 feet after hours and after hours.

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Asystem of equations has 1 solution.if 4x-y=5 is one of the equations , which could be the other equation ?