Which are the solutions of x2 = –13x – 4?

3(10x-y)-5(x-y^2) need this solved asap

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?

What is the value of x when x + 7 = 21?