What’s the equation of a line?

Choose the correct slope of the line that passes through the points (1, -3) and (3, -5)

The u-drive rent-a-truck company plans to spend $13 million on 320 new vehicles. each commercial van will cost $25 comma 000, each small truck $50 comma 000, and each large truck  $80 comma 000. past experience shows that they need twice as many vans as small trucks. how many of each type of vehicle can they buy?

[15 points, algebra 2]simplify the complex fraction and find the restrictions.