To solve this, I'm assuming that the equations both represent angles:
There is a theorem that states that an exterior angle of a triangle is equivalent to the sum of two remote triangles. Knowing this:
11x + 7 = 7x + 14 + 25
11x + 7 = 7x + 39
4x = 32
x = 8
Kinetic energy possessed by moving train is

.
And mass

.
The formula for kinetic energy is

.
Solve for velocity:


Now put in the data:
Answer:
20 pounds divided by $4= 5
Step-by-step explanation:
Answer:

Step-by-step explanation:
÷ 4 =
x
= 
When you have a fraction divide a number, you need to multiple it's reciprocal