Answer:
After 7 hours Tevin will catch Enrique
Step-by-step explanation:
We have given speed of Enrique is 20 mph
Tevin left traveling after 2 hours of Enrique
Speed of Tevin is 28 mph
When Tevin catches Enrique will cover same distance
Let Enrique is traveling for t hours
Then Tevin will travel for t-2 hours
We know that distance = speed × time
So 
t = 7 hours
So after 7 hours Tevin will catch Enrique
The path is in the shape of a parabola, the horizontal length is 24, so the middle point is at x=12, the symmetry line is x=12, the highest point (the vertex) is at (12,6)
the equation in vertex form is y=a(x-12)²+6
next, find a by using either one of the two points, the starting point (0,0) or the end point (0,24). obviously (0,0) is easier to calculate:
0=a(0-12)² +6
a=-1/24
so the quadratic equation is y=-
Okay. 10^12 is 1 trillion. 1 trillion * 7 is 7 trillion. 14 trillion / 7 trillion is 2. The national debt in 2010 is two times larger than in 2003. So that basically means that the national debt doubled from 2003 to 2010.
